BFIX Project vs Stack
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
BFIX Project
This app offers personalized coaching for joint pain, rehabilitation, and posture correction. It connects you with a coach for tailored workout and diet plans, and syncs with Apple HealthKit for activity tracking.
- Personalized online coaching
- Custom workout programming
- Mobility and rehab exercises
- Personalized diet plans
- Apple HealthKit synchronization
- Direct chat with coach
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What can you expect? Feeling joint pain? Requiring Rehab? Want to fix your posture? Take your health to the next level. Get a personalized coaching experience with BFIX Project. - Person-to-Person online coaching with your coach - Workout programming, Mobility and Rehab specific to your goals - Follow Diet plans and nutrition personalized by your coach - Synchronize your daily steps and active calories from Apple HealthKit - Direct Chat & Support with your coach
Stack
This app helps you build and complete habits within a 90-day timeframe. It focuses on finishing cycles rather than perpetual tracking, with a limit of three habits at a time. The interface uses a grid to mark progress, and a widget provides quick access to daily tasks.
- Three habit limit
- 90-day completion cycles
- Manual grid progress tracking
- Home-screen widget
- One honest skip per week
- No accounts or data collection
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Stack is a habit tracker with a finish line. Three habits. Ninety days. Then it is done. The stack ships, archives, and you start fresh. The cap of three and the ninety days are not limits to pay past. They are the point. Most habit apps are built to keep you forever. Stack is built to end. - Three habits. No more. The limit is the feature. - Ninety days. A clean quarter, then a finish line. - One honest skip a week. It holds your streak but shows as a skip, never a fake fill. - The grid is the app. Ninety days of dots, filled in by hand. - A home-screen widget with today's three. Tap to mark. - Built in Liquid Glass for iOS 26. No accounts. No subscription. No analytics. Zero data collected. Pay once. It is yours. From hsla0001, an independent studio in New York. Void captures. Loop times. Protocol scores the room. Stack holds intent.
Screenshots
Verdict
The clearest difference is price: BFIX Project at Free against Stack's $6.99. BFIX Project also leads on device support (3 vs 1) and ratings volume (3 vs 1). Stack's advantage is update cadence (daily vs every 3 months) and chart position (#199 vs unranked). On rating, 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
BFIX Project is free to download; Stack costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for BFIX Project against 5.0 for Stack. Both are backed by a comparable volume of ratings — 3 and 1 respectively.
BFIX Project ships an update every 3 months, Stack daily. The most recent releases landed on September 13, 2026 and August 7, 2026 respectively.
| Parameter | BFIX Project | Stack |
|---|---|---|
| Price | Free — better | $6.99 |
| Rating | 5.0 (3 ratings) | 5.0 (1 ratings) |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 3 — better | 1 |
| Update frequency | Every 3 months | Daily — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Best chart rank | — | #199 — better |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 169 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | lvlup-app, Inc. | hsla0001 |
Customer experience
BFIX Project
Stack
In-app purchases
BFIX Project
No in-app purchases
Stack
No in-app purchases
