Comparison

Stack Influence vs Letterss

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Stack Influence

Connect with brands for free products and cash back by sharing on social media. This platform offers instant approvals for creators with over 100 followers and provides opportunities for long-term brand partnerships.

Highlights
  • Freebies and cash back deals
  • Affiliate and brand ambassador opportunities
  • Instant approval with 100+ followers
  • Effortless posting and automatic payouts
  • Instant matchmaking with relevant brands
  • Build long-term brand relationships
Features
Read full description

Stack Influence gets you freebies, free samples, cash back deals, discounts, affiliate and brand ambassador opportunities. Simply post on social media in exchange for free stuff. Stop DMing brands and get influencer collabs that come to you. KEY FEATURES: • Stop Waiting for Approvals: You only need +100 followers to get approved within 24 hours! Avoid the wait and uncertainty with other platforms - Stack Influence lets you join UGC campaigns instantly and pays you automatically after you post. • Effortless Process: Download the app, answer a few quick questions and start receiving free stuff. Post your honest feedback on Instagram and get 100% cash back instantly—no delays or hidden fees! • Instant Matchmaking: Get paired with top brands that match your lifestyle and preferences. Whether it’s makeup, skin care, fashion, or home - find freebie deals you love and create long term brand ambassador / affiliate relationships! WHY STACK INFLUENCE? • Top Influencer Community: Join over 100,000 UGC creators and influencers. We’ve paid out over $4M in cash and delivered hundreds of thousands of freebie products. • Simple and Transparent: No partial discounts, no cash back delays, and no ambiguous terms. What you see is what you get—and what you get is free stuff from top brands. • Build Your Brand: Not just a one-time transaction—create lasting brand ambassador and affiliate relationships that grow your social media following and influenster career. 5 STAR REVIEW ON TRUSTPILOT: “I am a content creator on social media - primarily Instagram. I have been promoting products through Stack Influence for 7 months now and have been BLOWN away by how fun and professional they are to work with. They have multiple products you get to pick from. You first have to purchase the item yourself, then there are requirements that must be met to receive your payout. Examples are: you have to show your face with the product, you have to do it within a timeline, you have to include certain hashtags, etc. Once you do all the requirements you “Submit your Post” and they send the money to your PayPal account. I have received every payout!! It’s all very simple and thoroughly explained.” BECOME A STACK INFLUENCER TODAY: Don’t miss out on the opportunity to elevate your influenster potential. Join the leading USA influencer community – download Stack Influence today and start getting freebie deals from the world’s top brands!

About

Letterss

Features
Read full description

Letterss is transformative for the individual and revolutionary for society. Here are the rules: * Each letter must be at least 300 words * Letters take three days to arrive * It’s turn-based: only one letter can be in flight at a time Other features: * Attach an image to letters * Saved drafts you can come back to * Letter history saved with each friend * Phone-number sign-up only: no email, no public profile, no social graph * Friend-to-friend communication: only people you’ve accepted can write to you * Built-in block, report, and account-deletion tools END-TO-END ENCRYPTION Your letters are private. Letters are encrypted on your device. Only you and the person you wrote to can read them. * Industry-standard cryptography: AES-GCM + Curve25519 ECDH (Apple CryptoKit) * A fresh ephemeral key for every letter * Letterss servers cannot read your letters: neither can the network, nor anyone else * Even if the database were compromised, your letters would remain encrypted TRANSFORMATIVE FOR THE INDIVIDUAL The fast pace of modern life leaves little room for deep reflection. We rush from one thing to the next without fully thinking about what we’re doing. Writing, more than simply thinking, forces reflection. It gives shape to thoughts that would otherwise remain half-formed. Through deeper reflection, you begin to see things from different perspectives and act more carefully on what truly matters. Over time, you may notice: * You think and write more clearly * You feel more connected to your friends and family * You stop scrolling social media the way you used to REVOLUTIONARY FOR SOCIETY Social media stopped being social a long time ago. What began as a way to stay connected is now an algorithm that rewards our worst impulses and leaves us doom-scrolling for the next hit. We are no longer truly connecting. We are consuming a counterfeit connection that is exciting at first, but empty over time. Imagine the difference between junk food and a healthy, nourishing meal. Both fill the stomach, yet only one truly satisfies. Junk food is engineered to keep you hungry, and social media works the same way. Writing letters, by contrast, is nourishing. It is an authentic human experience that creates a real connection with another person. You may not quit social media overnight, but engaging in something meaningful can gradually make the artificial feel less appealing. There is also the matter of writing itself. Humans have been writing for thousands of years. It is how civilizations think, remember, and discover themselves. Now, in the digital age, AI is replacing the act of writing. Emails, homework, even thinking itself are increasingly outsourced. Allowing that habit to die may cost society more than we realize. Some people believe that AI will be the driving force behind a better world and productivity. But if AI takes us further away from reality, we will be left worse off. Real progress requires genuine human connection and active engagement with the real world. Intelligence shaped through lived experience will always be more powerful than artificial intelligence. Letterss is this idea materialized. 
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Screenshots

Stack Influence4 screens
Letterss4 screens

Verdict

The call

The clearest difference is update cadence: Letterss at weekly against Stack Influence's monthly. Stack Influence's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.5). On price, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Stack Influence ships an update monthly, Letterss weekly. The most recent releases landed on October 16, 2026 and October 8, 2026 respectively.

Scorecard3 real differences · 7 level
Stack Influence versus Letterss: the parameters behind the verdict, then further details
ParameterStack InfluenceLetterss
PriceFreeFree
Rating4.3 (397 ratings) — better—
Positive reviews78.0% of reviews—
Number of ratings397 — better—
Update frequencyMonthlyWeekly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.0 — better17.5
Further details — not scored
Size43 MB8 MB
Age rating17+17+
DeveloperStack InfluenceBetitup Gaming, Inc

Bugs and requests

Stack Influence

Reported bugs

2 issues
  • Issues with verification code delivery
  • Inconsistent campaign availability

Requested features

3 requests
  • Expand to TikTok platform
  • Offer paid content opportunities
  • Improve campaign selection and availability

Letterss

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Stack Influence

No in-app purchases

None

Letterss

No in-app purchases

Questions

Is Stack Influence free?
Stack Influence is free to download, with no in-app purchases.
Is Letterss free?
Letterss is free to download, with no in-app purchases.
Do Stack Influence or Letterss have ads?
Neither Stack Influence nor Letterss shows ads.
Which is updated more often, Stack Influence or Letterss?
Stack Influence ships an update monthly, and Letterss weekly. Most recently, Stack Influence was updated on October 16, 2026 and Letterss on October 8, 2026.

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