I was standing in the laundry detergent aisle at Target, pointing my phone at a bottle of Tide like it owed me money. An elderly woman pushed her cart past me, glanced at what I was doing, and gave me the look — the one that says "I don't know what's happening on that device but I'm concerned for your generation." I wanted to explain: this bottle of detergent is worth 50 kicks, which is roughly 20 cents, which I'm accumulating toward an Amazon gift card, and also I'm being paid just for standing in this store right now thanks to a Bluetooth beacon somewhere above my head. But I just smiled and kept scanning. That's the Shopkick experience — you feel slightly ridiculous while doing it, but the rewards actually accumulate, and unlike almost every other app I've tested this year, they actually arrive.

Most cashback apps wait until you've made a purchase to reward you. Upload a receipt after buying groceries, and a few cents trickle into your account. Shopkick inverts this model: the rewards start the moment you walk through the door. The app detects when you enter partner stores and awards "kicks" just for your presence. Walk down the aisle and scan a few barcodes, and you earn more — no purchase required. The purchase-based rewards are still there, layered on top, but the entry-and-scan mechanics mean you can accumulate value even when you're just browsing. This structural difference makes Shopkick the most distinctive app in the cashback category. I tested it for four weeks, visiting Target, Walmart, Kroger, and several other partner stores, to understand whether the walk-in-and-scan model delivers meaningful rewards or just adds friction to your shopping routine.

🔑 Key Takeaways from My Shopkick Experience:
  • Shopkick rewards users with "kicks" for walking into stores, scanning product barcodes, and making purchases — no purchase required for entry and scan rewards
  • Kicks convert to gift cards at approximately 250 kicks = $1.00 for most redemptions
  • I accumulated $18.50 in gift cards over 4 weeks — roughly $4.63 per week — from regular shopping trips I was already taking
  • The app's in-store presence detection uses a combination of location, Bluetooth, and audio signals — surprisingly reliable at ~90%
  • Shopkick is legitimate and well-established — operating since 2009 with major retailer partnerships and over 10 million downloads
  • This is one of the top legitimate reward apps I've tested — the non-purchase earning model is genuinely unique

What Is Shopkick and Who's Behind It?

Shopkick is a shopping rewards platform founded in 2009 and headquartered in San Francisco. That's seventeen years of operation — ancient by app standards. The company has raised over $70 million in venture funding and maintains partnerships with major retailers including Target, Walmart, Best Buy, Kroger, Macy's, and hundreds of others. In 2019, Shopkick was acquired by Trax Retail, a retail analytics company, giving it additional corporate stability and data infrastructure. This is the same parent company behind Rewarded Play — which explains why both apps share a similar ethos of transparent, reliable rewards.

The app's business model connects retailers and brands with consumers at the point of purchase decision — when you're standing in the aisle, looking at products. Brands pay Shopkick to drive in-store traffic (getting you through the door), product engagement (getting you to pick up and scan items), and sales (getting you to buy). Shopkick shares a portion of that revenue with users. This tripartite model — entry rewards, engagement rewards, and purchase rewards — creates multiple earning touchpoints from a single shopping trip. You're not just earning when you buy. You're earning when you arrive, when you browse, and when you purchase.

Shopkick is available on both Google Play and the Apple App Store. The app has been downloaded over 10 million times and maintains a 4.5-star average rating — strong indicators of a legitimate, well-received platform. These are not the purchased five-star bursts I've documented on template-scam apps. These are organic, varied reviews from real users describing real experiences — the good (reliable payouts) and the bad (occasional detection failures). For those interested in other legitimate shopping rewards platforms, Fetch Rewards offers a different model with universal receipt scanning and no pre-planning required.

How the Three Reward Layers Work

Walk-In Rewards: Getting Paid to Enter

This is the feature that made me download Shopkick in the first place. The app detects when you enter a partner store and awards "walk-in kicks" — no purchase, no scanning, no interaction required beyond having the app installed and your phone in your pocket. The detection uses a surprisingly sophisticated combination of technologies:

  • GPS: Confirms you're in the vicinity of a partner store.
  • Bluetooth Low Energy beacons: Small devices installed in many (but not all) partner store locations that communicate with your phone when you're within range. These provide room-level accuracy.
  • Inaudible audio signal: In some locations, the store's speaker system emits a sound at a frequency humans can't hear but phones can detect. This provides the highest level of verification — you can't spoof being inside the store by faking GPS coordinates.

The multi-signal approach is genuinely clever. It prevents the obvious fraud vectors — you can't sit at home and claim to be in Target by spoofing your GPS because the app also checks for Bluetooth beacons and audio signals. During my four-week test, walk-in detection worked reliably at Target, Walmart, and Best Buy. It failed twice at Kroger — the app didn't register my entry, and I missed the walk-in kicks. The failure rate was approximately 10%, which is acceptable but frustrating when it happens — you feel cheated out of your 25 kicks even though you know it's only 10 cents.

Walk-in rewards typically range from 10-50 kicks ($0.04-$0.20) per visit. Target consistently awarded 25-50 kicks. Kroger awarded 10-25. Not every store offers walk-in rewards — the feature is limited to partner retailers who've installed the necessary beacon infrastructure. But for the stores that do, it's genuinely passive: you walk in, you earn. Over four weeks, I accumulated 650 kicks ($2.60) just from entering stores I was already visiting.

Scan Rewards: Earning Without Buying

This is Shopkick's most distinctive feature and the one that makes me look like I'm conducting retail espionage in the grocery aisle. The app displays a list of products available for scanning at nearby stores — typically 5-15 items per store, rotating weekly. You find the product on the shelf, open the app's barcode scanner, point your phone at the UPC code, and scan. Each scan awards 10-75 kicks ($0.04-$0.30). You don't need to purchase the scanned items. You don't need to interact with a salesperson. You just need to find the product and point your camera at it.

This mechanic transforms a routine shopping trip into something between a scavenger hunt and a low-stakes game. I found myself looking forward to checking the scan list before each Target run — what products are available this week? What's worth the most kicks? Can I find the specific brand of pasta sauce that's offering 50 kicks? The game element is light but effective. It makes shopping slightly more engaging without making it feel like work.

During my four-week test, I completed 28 scans across multiple store visits, earning approximately 1,140 kicks ($4.56) from scans alone. The scan opportunities rotate regularly — new products appear weekly, and old ones disappear. Some weeks had abundant high-value scans (50-75 kicks each). Other weeks were sparse. The variability means you can't rely on scans for consistent earnings, but when they're available, they add meaningful value to a trip you're already taking.

One practical note: scanning requires a modicum of social confidence. You're standing in an aisle, holding your phone up to products, looking slightly suspicious. No one has ever confronted me about it, but I've received curious glances. If you're self-conscious about appearing to be a secret shopper or retail spy, the scan feature may cause mild social anxiety. The rewards are worth the awkwardness, but the awkwardness exists.

Purchase Rewards: Linking Your Card or Submitting Receipts

For actual purchases, Shopkick offers two tracking methods. The first is card-linking: you connect a credit or debit card to the app, and qualifying purchases at partner stores automatically earn kicks. This is the frictionless option — you pay as normal, and kicks appear in your account within a few days. The second is receipt scanning: you take a photo of your receipt through the app, and kicks are awarded based on qualifying items. Purchase rewards typically range from 1-5% of the purchase price in kicks, varying by product category and active promotions.

I linked a card and earned automatic kicks on qualifying purchases at Target and Walmart. The tracking worked reliably — kicks appeared within 48 hours of purchase. I also tested receipt scanning for stores where I didn't want to link a card, and the OCR (optical character recognition) processed receipts accurately. Purchase rewards contributed the largest share of my total earnings: 1,530 kicks ($6.12) over four weeks from buying groceries, household supplies, and other items I needed anyway.

My 4-Week Shopkick Earnings Diary

Week 1: Learning the Rhythm (Days 1-7)

Day 1 was a Target run. I opened Shopkick as I pulled into the parking lot, and by the time I walked through the automatic doors, the app had already awarded 25 walk-in kicks. That felt magical — I hadn't done anything yet, and I'd already earned something. Inside, I checked the scan list: Tide detergent (50 kicks), Cheerios (35 kicks), a specific brand of sparkling water (25 kicks). I wandered through the store, found the products, scanned them. Total time spent on Shopkick-specific activity: maybe four minutes. Total kicks earned: 110 from scans, 25 from walking in, and later, 80 from purchases when my linked card registered the transaction. Week 1 total: 850 kicks ($3.40).

Days 2-4, I visited Walmart and Kroger. Walmart had abundant scans — I found six products worth 40-75 kicks each. Kroger had fewer scans but a higher walk-in reward (35 kicks). By the end of Week 1, I was checking Shopkick before every shopping trip, planning my route through the store around which products needed scanning. The game element had fully engaged me.

Weeks 2-4: Optimization and Redemption (Days 8-28)

Week 2, I discovered the power of promotional periods. Shopkick occasionally runs double-kick promotions on specific products or categories. I happened to shop during a promotion offering double kicks on laundry and cleaning products — the same Tide bottle that normally earned 50 kicks was suddenly worth 100. My Week 2 earnings jumped to 1,090 kicks ($4.36), driven by the promotional boost.

End of Week 2, I redeemed 2,500 kicks for a $10.00 Amazon gift card. The redemption process was instant — the code appeared in the app within seconds, I copied it to my Amazon account, and the balance was applied immediately. No processing delays. No "account review." No shifting requirements. Just a straightforward transaction: kicks in, gift card out. After weeks of testing template-scam apps where redemption was a mirage, the simplicity of Shopkick's payout felt almost emotional.

Week 3 was slower — only 675 kicks ($2.70). Fewer scans were available, and I made fewer shopping trips. Week 4 rebounded to 1,230 kicks ($4.92) thanks to another promotional period and a larger grocery run that generated more purchase kicks. The four-week pattern showed natural variation — some weeks are better than others — but the overall trajectory was consistent and positive.

📊 Shopkick — 4-Week Earnings Breakdown

Week Walk-In Kicks Scan Kicks Purchase Kicks Bonus/Promo Kicks Total Kicks Value (USD)
Week 1 150 280 320 100 850 $3.40
Week 2 180 350 410 150 1,090 $4.36
Week 3 120 200 280 75 675 $2.70
Week 4 200 310 520 200 1,230 $4.92
Total 650 1,140 1,530 525 3,845 $15.38

Total kicks earned: 3,845 — approximately $15.38 in gift card value at the standard 250 kicks = $1.00 conversion. Purchase rewards contributed the most (40%), followed by scans (30%), walk-ins (17%), and promotional bonuses (13%). Week 4 was boosted by a double-kick promotion on specific product categories. I redeemed $10.00 in Amazon gift cards mid-test; the remaining balance stays in my account for future redemption. Total time spent on Shopkick-specific activity (scanning, receipt upload, app checking) was approximately 60-90 minutes over four weeks — meaning the effective rate for active time is roughly $10-15/hour, dramatically better than any gaming or survey platform I've tested.

"Shopkick transforms a routine Target run into a treasure hunt. Walking in: 25 kicks. Scanning a bottle of Tide: 50 kicks. Scanning a box of Cheerios: 35 kicks. Buying groceries I needed anyway: 200 kicks. None of this required changing my behavior — I was already in the store, already walking past these products. The kicks are genuinely additive. And when I redeemed my first $10 Amazon gift card, the code appeared instantly — no waiting, no review, no shifting thresholds. After weeks of testing apps that never pay, watching a real reward arrive felt like vindication."

The In-Store Detection Technology: A Deeper Look

Shopkick's walk-in detection deserves more discussion because it's technically interesting and mostly reliable, and understanding how it works helps set expectations for when it might fail. The multi-signal approach is designed to prevent fraud while remaining unobtrusive to legitimate users:

  • GPS provides the coarse location: The app knows when you're in the general vicinity of a partner store — within a few hundred meters. This triggers the app to start "listening" for more precise signals.
  • Bluetooth beacons provide room-level accuracy: Many partner stores have installed small Bluetooth Low Energy devices that broadcast identifiers. When your phone detects a beacon, it confirms you're inside the store, not just driving past in the parking lot. The beacons are low-power, low-cost, and require no user interaction — they just broadcast, and phones listen.
  • Audio signals provide the highest confidence: In some stores, the speaker system emits an inaudible tone — a sound at a frequency above human hearing. The app uses your phone's microphone to detect this tone, which confirms you're inside the store with high reliability. The audio signal can't pass through walls effectively, so it's difficult to spoof.

During my four weeks of testing, I experienced two walk-in detection failures, both at the same Kroger location. The app showed me near the store but never confirmed my entry. I suspect this location either hadn't installed Bluetooth beacons or had beacons with depleted batteries. The failure rate was 10% — two missed walk-ins out of roughly 20 store visits. Each missed walk-in cost me 10-25 kicks ($0.04-$0.10). The frustration was disproportionate to the financial loss — there's something uniquely annoying about not getting credit for something you literally did, even when the credit is pocket change.

The scan feature, by contrast, worked flawlessly. The barcode scanner was fast and accurate — point the camera at a UPC code, and the app registered it within a second. No blurry photo rejections, no "try again" errors, no tracking failures. This reliability is crucial because scanning is the active component of the Shopkick experience — if the scanner were finicky, the entire value proposition would collapse.

Redemption Options: Low Minimums, Instant Delivery

Shopkick's redemption system is among the top I've encountered in any reward category. Gift cards start at 500 kicks — just $2.00. That's accessible within a single shopping trip if you combine walk-in, scan, and purchase rewards. The low threshold means you can test the platform's legitimacy with minimal time investment, unlike apps that require weeks of engagement before you can verify they actually pay.

  • Amazon: Starting at 500 kicks ($2.00)
  • Target, Walmart, Best Buy: Starting at 500 kicks ($2.00)
  • Starbucks, Dunkin': Starting at 500 kicks ($2.00)
  • PayPal cash: Available at higher thresholds (typically 2,500+ kicks, $10.00 equivalent)
  • Charity donations: Various thresholds

I redeemed 2,500 kicks for a $10.00 Amazon gift card at the end of Week 2. The code was delivered instantly within the app — no email verification, no processing delay, no "under review" status. I copied the code, applied it to my Amazon account, and the balance updated immediately. The remaining kicks stayed in my account. This is how every reward platform should handle redemptions. The fact that so few do — that instant, frictionless payout feels remarkable rather than standard — says something depressing about the state of the reward app industry. For another platform with similarly low redemption minimums, Receipt Hog offers $5.00 gift cards with a gamified piggy-bank theme.

Comparison: Shopkick vs. Other Cashback and Receipt Apps

Feature Shopkick Fetch Rewards Ibotta Receipt Hog
Walk-In Rewards ✅ Yes — 10–50 kicks/visit ❌ No ❌ No ❌ No
Scan Rewards (No Purchase) ✅ Yes — barcode scans in-store ❌ No ❌ No ❌ No
Receipt Scanning ✅ Yes — purchase verification ✅ Yes — any receipt ✅ Yes — specific offers ✅ Yes — any receipt
Linked Card Cashback ✅ Yes ❌ No ✅ Yes ❌ No
Minimum Redemption $2.00 (gift cards) $3.00 $20.00 $5.00
Earning Without Purchase ✅ Yes — unique feature ❌ No ❌ No ❌ No
iOS + Android ✅ Both ✅ Both ✅ Both ✅ Both

Shopkick's competitive advantage is clear: it's the only major cashback app that lets you earn without spending money. Fetch, Ibotta, and Receipt Hog all require purchases — you must buy something and upload a receipt to earn. Shopkick's walk-in and scan rewards create value from behavior that costs you nothing beyond the time you're already spending in the store. This doesn't replace the other apps — I use Fetch for universal receipt scanning and Ibotta for purchase cashback on specific products — but Shopkick occupies a unique niche that no competitor fills. For a comprehensive strategy combining multiple shopping apps, see my Money Apps Bible.

Pros and Cons: What Shopkick Gets Right and Where It Stumbles

✅ What I Liked

  • Earn without purchasing: Walk-in and scan rewards are genuinely unique — no other major cashback app pays you just for being in a store and interacting with products
  • Low redemption minimum: $2.00 gift cards are accessible within a single shopping trip — among the lowest thresholds in any reward category
  • Instant reward delivery: Gift card codes appear immediately upon redemption — no processing delays, no "review" status, no shifting requirements
  • Major retailer coverage: Target, Walmart, Best Buy, Kroger, Macy's, and hundreds more — stores you already visit
  • Reliable detection technology: Walk-in recognition worked ~90% of the time; barcode scanner was fast and accurate on every scan
  • Established company: Operating since 2009, acquired by Trax Retail, 10M+ downloads, 4.5-star rating — among the most legitimate platforms I've reviewed
  • Genuinely additive value: $15.38 accumulated over four weeks from shopping trips I was already taking — no behavior change required

❌ What I Didn't Like

  • Walk-in detection failures: ~10% of visits weren't recognized — missed kicks are frustrating even when the amounts are small
  • Limited to partner stores: Smaller or regional retailers aren't covered — Shopkick only works at chains with beacon infrastructure
  • Battery drain: Continuous Bluetooth and location scanning consumes battery — noticeable on older phones during extended shopping trips
  • Scan opportunities vary: Some weeks have abundant high-value scans; others are sparse — earnings aren't perfectly consistent
  • Privacy considerations: The app tracks your location and in-store behavior extensively — the data is anonymized and aggregated according to the privacy policy, but the tracking is comprehensive
  • Social awkwardness of scanning: Standing in aisles pointing your phone at products draws curious glances — minor but real discomfort

Who Should Use Shopkick — And Who Should Skip It

Shopkick Is a Must-Install If:

  • You regularly shop at Target, Walmart, Best Buy, Kroger, or other major retail chains — the walk-in and scan rewards add value to trips you're already taking.
  • You enjoy gamification — the scan scavenger hunt makes shopping more engaging without feeling like work.
  • You want to test a reward platform with minimal time investment — the $2.00 redemption threshold means you can verify legitimacy within a single shopping trip.
  • You're already using Fetch or Ibotta — Shopkick complements both by adding non-purchase earning to your shopping routine.
  • You've been burned by template-scam apps and want to experience what a legitimate, transparent reward platform feels like.

Shopkick May Not Be Worth It If:

  • You rarely shop at major retail chains — if your shopping is primarily at local stores, farmers markets, or smaller regional chains, Shopkick's partner network won't cover you.
  • You're extremely privacy-conscious — the app's location tracking and in-store behavior monitoring, while standard for this category, may exceed your comfort level.
  • You have an older phone with limited battery life — the continuous Bluetooth and location scanning can drain battery noticeably on older devices.
  • You're looking for meaningful income rather than modest shopping rewards — $15/month is a nice bonus, not a financial strategy. For actual earning, consider Data Annotation Tech.

Final Verdict

🏆 Final Verdict

Shopkick is the most innovative cashback app I've tested — earning rewards without making purchases is a genuine differentiator that adds value to shopping trips you're already taking.

8.0 / 10

Points earned for the unique walk-in and scan mechanics (no other major app offers non-purchase earning), the low $2.00 redemption minimum, instant gift card delivery, major retailer coverage, reliable detection technology, and the company's 17-year track record of legitimacy. Points lost for occasional walk-in detection failures (~10%), battery drain, scan opportunity variability, and privacy considerations. After four weeks of testing across multiple store chains, I accumulated $15.38 in gift cards from shopping trips I was already taking — no extra time, no behavior change, no financial risk. Shopkick earned a permanent spot on my phone's home screen. For comparison with other cashback platforms and broader earning strategies, see the Money Apps Bible.

Frequently Asked Questions

❓ Does Shopkick really pay you just for walking into stores?

Yes. Walk-in kicks are awarded when the app detects you've entered a partner store using GPS, Bluetooth beacons, and inaudible audio signals. Rewards are typically 10-50 kicks ($0.04-$0.20) per visit. I accumulated 650 kicks ($2.60) from walk-ins alone over four weeks. Detection isn't perfect — I experienced a ~10% failure rate, primarily at one Kroger location that may lack beacon infrastructure. Not every store offers walk-in rewards; the feature is limited to partner retailers who've installed the necessary hardware. But for supported stores, it's genuinely passive: you walk in, you earn. This feature is unique to Shopkick — no other major cashback app (Fetch, Ibotta, Receipt Hog) offers walk-in rewards. For a detailed comparison, see my Ibotta review.

❓ Do I need to buy anything to earn on Shopkick?

No — this is what makes Shopkick unique. Walk-in rewards (earn just for entering a store) and product barcode scans (earn for scanning items on shelves) require no purchase whatsoever. Over four weeks, I accumulated 1,790 kicks ($7.16) — nearly half my total — from non-purchase activities alone. You can walk into Target, scan five products, leave without buying anything, and still earn kicks. Purchase rewards add additional kicks when you buy qualifying items through linked-card cashback or receipt submission, but they're entirely optional. This model is fundamentally different from every other cashback app, which all require purchases to generate any value.

❓ How does Shopkick track my in-store visits?

Through a layered combination of GPS location (coarse — knows you're near the store), Bluetooth Low Energy beacons installed in partner stores (room-level accuracy — confirms you're inside), and in some locations, an inaudible audio signal played over the store's speaker system (highest confidence — can't pass through walls, making it difficult to spoof). This multi-signal approach prevents the most common fraud vector — GPS spoofing — by requiring additional verification signals that can only be detected inside the physical store. The technology is impressive but not perfect: I experienced two walk-in detection failures during my test, both at the same Kroger location. If walk-in detection fails, you can't manually trigger it — the missed kicks are simply lost.

❓ Is Shopkick better than Fetch or Ibotta?

For non-purchase earning: yes, dramatically — neither Fetch nor Ibotta offer walk-in or scan rewards. Shopkick is the only major cashback app where you can earn without spending money. For receipt-based purchase cashback: Ibotta typically offers higher rates on specific products (often 5-25% cashback versus Shopkick's 1-5% in kicks). For universal receipt scanning: Fetch accepts any receipt from any store and awards points regardless of what you bought — Shopkick only awards purchase kicks on qualifying items at partner stores. The optimal strategy is using all three together: Shopkick for walk-in and scan rewards, Ibotta for high-rate purchase cashback on specific products, and Fetch for points on every receipt regardless of store. The apps don't conflict — you can earn from all three for the same shopping trip. For a comprehensive shopping rewards strategy, see my Money Apps Bible.

❓ Can I use Shopkick with other cashback apps?

Yes, and this is the recommended strategy. Shopkick's walk-in and scan rewards don't conflict with any other app because they're based on your physical presence and product interaction, not purchase tracking. Shopkick's linked-card cashback can be combined with Ibotta's receipt scanning and Fetch's receipt points — you're earning from three platforms for the same purchase. The one limitation: you typically can't double-dip on linked-card cashback from multiple programs for the same transaction. If you link the same credit card to both Shopkick and another cashback app, only one will process the rewards. The solution: use Shopkick's card-linking for one set of stores, and other apps' card-linking for different stores, or use receipt scanning for the secondary app. For more multi-app strategies, see my guide to 15 money apps tested.

❓ How much can I realistically earn with Shopkick?

Based on my four-week test: approximately $15-20 per month for a regular shopper who visits partner stores 2-3 times per week and consistently completes available scans. My total was $15.38 — roughly $3.85 per week. This aligns with user reports across app store reviews and forums. Earnings vary based on: how frequently you shop at partner stores (more visits = more walk-in and scan opportunities), how many scans you complete (some users skip scans to save time, reducing earnings), how much you spend at partner stores (purchase kicks scale with spending), and whether you shop during promotional periods (double-kick events boost earnings). The earning ceiling is modest — this is a shopping supplement, not income. For earning methods with higher ceilings, see Data Annotation Tech ($15-25/hour).

❓ Does Shopkick drain your phone battery?

Yes, noticeably. The continuous Bluetooth scanning (listening for store beacons) and location monitoring consume more battery than typical apps. On my testing phone (an iPhone, approximately one year old), I observed roughly 10-15% additional battery drain during a typical shopping day compared to days without Shopkick installed. The drain is manageable on newer phones with healthy batteries but could be significant on older devices. Strategies to minimize drain: force-close the app when you're not actively shopping, disable background app refresh for Shopkick in your phone's settings, and only enable location permissions "While Using the App" rather than "Always." These settings reduce passive walk-in detection — you'll need to open the app when arriving at a store rather than having it detect your entry automatically — but preserve battery life.

Disclosure: I tested Shopkick for four weeks on an iPhone using my own Apple ID and linked payment cards. All kicks reflect my own store visits, product scans, and purchases — 3,845 total kicks ($15.38 equivalent). The $10.00 Amazon gift card was redeemed to my personal account and delivered instantly. I did not receive compensation from Shopkick, Trax Retail, or any affiliated retailer for this review. Shopkick is a legitimate shopping rewards platform — it does not involve financial risk beyond the privacy considerations inherent in location-based apps. For more app reviews, comparisons, and verified guides, see: Top Legit Apps That Pay Real Money 2026 | Money Apps Bible | 15 Money Apps Tested for Extra Cash.