Privacy Policy

The Short Version

Your workout data stays on your device. We collect anonymous usage analytics (e.g. "a workout was completed") to improve the app. We don't sell your data or run ads.

Data Storage

RepStack stores all your data locally on your device using SQLite. Your workouts, programs, exercises, personal records, and settings never leave your phone unless you explicitly enable iCloud Sync.

• Workout logs, exercise data, and preferences are stored in a local SQLite database
• If you enable iCloud Sync, your data syncs across your Apple devices via CloudKit — Apple handles the encryption and transport
• We have no server-side database of your workout data

AI Processing

RepStack uses AI for coaching suggestions and program import parsing. Physique Score, which analyzes a progress photo, is covered in its own section below.

• When generating coaching advice, your recent set data (weight, reps, exercise name) is sent to Anthropic's Claude API to generate suggestions
• When importing a program, the text or spreadsheet content you provide is sent to Anthropic's API for parsing
• No personal information (name, email, location) is included in these requests
• Anthropic does not use API inputs for model training
• The local rule engine works fully offline — AI coaching is an optional enhancement

Physique Score and Progress Photos

Physique Score is an optional AI analysis for progress photos you capture or import. It rates visible muscle-group development on RepStack's 0–999 scale and suggests changes to your training. It reads the photo, not the person, and AI analysis is available only to adults (18+). Saving progress photos does not require AI analysis.

• Saved progress photos and their scores remain in a local database on your device and are not included in iCloud Sync
• Only when you choose Analyze, a normalized copy is sent once through our scoring service and analyzed by an AI vision model provided by OpenAI
• That copy is used only to generate the analysis and is discarded immediately afterward — we keep no server-side copy of your photos, and OpenAI does not use these API inputs to train its models
• Analytics for this feature record only metadata — such as the overall score, confidence, and which poses were scored — never the image itself
• You can delete any scan from within the app, and deleting the app removes all saved progress photos and scores

Analytics

RepStack uses PostHog to collect anonymous usage analytics — things like whether you started a workout, finished it, or viewed the paywall. This helps us understand which features people actually use and where the app breaks down.

• No personal information (name, email, workout data, weights, or reps) is sent to PostHog
• Events contain only anonymous action data (e.g. "a workout was completed with 5 exercises")
• PostHog does not sell data or use it for advertising
• We do not use advertising SDKs, tracking pixels, or fingerprinting

Payments

Subscriptions are processed through Apple's App Store. We use RevenueCat to manage subscription status. RevenueCat receives an anonymous device identifier — no personal data. We never see your payment details.

App Store Data

Apple may collect anonymized usage data as part of the App Store and iOS ecosystem. This is outside our control and governed by Apple's privacy policy.

Data Deletion

You own your data. To delete it:

• Delete the app — all local data is removed
• If you used iCloud Sync, data in iCloud is managed through your Apple ID settings
• To request data deletion, email [email protected]

Children's Privacy

RepStack does not knowingly collect data from children under 13. Since we don't collect personal data, there is no data collection to regulate under COPPA.

Changes

If we update this policy, we'll post the new version here with an updated date. Material changes will be communicated in-app.

Contact

Questions? Email [email protected].