About this app
Stop guessing which supplements actually work. Run A/B tests on your own body. Built for gym rats who want evidence. You take five supplements. Maybe ten. You tweak your stack every time some influencer drops a video, and you still have no idea what's moving the needle. StackLab fixes that. Pick an experiment, train normally, and after a couple weeks the app hands you a percentage difference and a verdict instead of an opinion. FEATURES • Find out if creatine timing matters. The app alternates AM and PM days and tells you which one your body actually responds to. • See whether pre-workout is worth forty bucks a tub. Pre-workout days against clean days, side by side, with a verdict at the end. • Skip the manual workout log. Apple Health pulls in lifts, sleep, and resting heart rate the moment you finish a session. • Rate a session in five seconds. Four taps cover strength, energy, pump, focus. Done. • Get a clear answer. Each completed test ends with a verdict (positive effect, negative effect, or no clear difference) plus the percentage gap. • Catch noise before it lies to you. Sleep under five hours flags the session, so a rough night doesn't poison your data. • Watch the trend at a glance. A rolling seven-day Performance Score sits on the dashboard, so you see drift before you feel it. • Run more tests when you're ready. Free includes one active experiment. Premium unlocks unlimited tests, a custom builder, and the sleep-versus-performance correlation that separates lucky weeks from steady gains. HOW IT WORKS 1. Log your stack. Pick a template (pre-workout, creatine timing, fasted vs fed) or build your own. 2. Train normally. The app handles the alternation. Apple Health handles the data. 3. Read the result. After enough sessions, StackLab tells you what worked. PRIVACY Your data stays on your phone. No cloud sync, no accounts, no analytics SDK, no ads. HealthKit access is read-only, so the app cannot write to your health record. Stop paying for opinions. Test your own stack. Payment will be charged to your Apple ID at confirmation of purchase. Subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. You can manage and cancel your subscriptions in your Account Settings on the App Store after purchase. Any unused portion of a free trial is forfeited when purchasing a subscription. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://BigBalli.com/privacy
Latest release
What’s New
Improved & Fixed - Reduced unnecessary background activity for lighter battery use and better reliability
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Aug 16, 2026 · 10:04 PM Free