Getting started
What is Stackd?
Stackd is an iOS fitness tracker for people who design their workout programs with AI tools. Instead of building your program inside the app, you import it from JSON.
What's the JSON format Stackd expects?
Open the app and tap Import New on the Workout tab. There's a built-in prompt you can copy and paste straight into any AI chat agent — it includes the full schema.
Do I need an AI subscription to use Stackd?
No. The free tiers of any AI chat agent work great for generating programs. You can also write the JSON yourself if you want.
Features
How is e1RM calculated?
Epley formula: e1RM = weight × (1 + reps / 30). Calculated automatically per set, per exercise, after every session.
How does the progressive overload alert work?
Stackd implements the NSCA's 2-for-2 rule: hit the top of your prescribed rep range for two sessions in a row, and Stackd suggests adding 2.5kg next session. The alert is per-exercise.
Does it work offline?
Yes. Stackd is offline-first using SwiftData. Your programs, sessions, and nutrition logs live on your device.
Can I track nutrition?
Yes — log meals, follow a meal plan, and track macros, all in the same app.
Can I export my data?
Yes. Profile → Settings → Export Data lets you export programs, nutrition plans, and full session history as CSV.
Subscription & billing
How much does Stackd cost?
$1.99/month or $7.99/year (67% off). Full access on both — unlimited programs, nutrition, e1RM analytics, themes, and CSV export. No free tier.
Can I cancel anytime?
Yes. Settings → [your name] → Subscriptions on iPhone. Cancellation takes effect at the end of your current billing cycle.
Are there ads?
Never.
Troubleshooting
My import isn't working
Most failed imports come from extra commentary the AI added. Make
sure you're only pasting the JSON object (starts with {, ends with }) — no code fences, no preamble. Still stuck?
Ask in Discord.
My data disappeared
Stackd stores data on-device. If you reinstalled the app or moved phones without iCloud sync enabled, the data may not have transferred. Always export to CSV before reinstalling.
I found a bug
Sorry about that. Drop it in the Discord with a screenshot if you have one.