Privacy

This page covers the openGym apps for Android and iPhone (the APK from this site and GitHub, the Google Play and App Store versions) and this website. Last changed: 14 October 2026.

The short version

• No account. The app works without signing up anywhere.
• No analytics, no ads, no crash reporting, no tracking. Not in the app, not by us, not by anyone we work with. There is nobody we work with.
• Your training log stays on your phone. Workouts, plans, body weight, photos and settings are stored in the app's own storage on your device. We never receive them.
• You decide what leaves the phone, and only these things can: a backup you export, a server you connect, the AI coach if you set it up, and Health Connect or Apple Health if you switch it on.

When the app goes online

Only for these, and only once you set them up:

• Your own server. "Connect to my server" syncs your log with an openGym server you run or picked yourself. That server's operator, not us, is responsible for it; on your own server, that's you.
• The AI coach. Optional and off until you set it up with an API key from an AI provider of your choice (for example Anthropic, OpenAI or Google). Before the first request it shows which data it sends (your training history, plan, goals and the answers you gave it) and to which provider, and asks you. The request goes straight from your phone to that provider, under your key and that provider's privacy policy. Your name and other account details are never part of it. Using the coach of your own server instead, the request goes through that server to the provider its admin picked, and the app asks you about that provider the same way. Your answer is remembered on the device for that provider only: switch providers and it asks again, and you can take it back anytime in the coach's menu under AI data sharing. A model running on your own network is not a third party, so nothing to ask there.
• Health Connect (Android). If you switch it on, the app writes finished workouts and weigh-ins to Health Connect on your phone. It reads nothing from it.
• Apple Health and Apple Watch (iPhone). Off until you switch it on. Then the app saves finished workouts and weigh-ins to Apple Health, and during a workout the Apple Watch app reads your heart rate to show it next to each set. The watch talks to your iPhone directly. Health data is never sent to us and never used for advertising.
• Sharper animations (store versions). A basic set of exercise animations comes with the app. Sharper sets are optional downloads under Settings → Animation quality, delivered by Google Play or Apple like the app itself (on Auto, only over Wi-Fi).
• Missed-day reminder (only with your own server connected). In the background the app may ask your server whether you already trained today, so it doesn't nag you for nothing.
• Update check (only the APK from this site and GitHub). When you open Settings → About, the app asks GitHub's public release list whether there is a newer version, and downloads it from GitHub if you tap update. The store versions are updated by their store and never do this.

The built-in exercise animations are inside the app, so browsing exercises needs no connection. The camera is used only when you scan your gym membership code or take a photo or video of an exercise you add yourself; scanned images are read on the phone and never stored or sent. Notifications (workout reminder, end of a rest) are scheduled on the phone itself.

Deleting your data: it's on your phone, so Settings → Reset or uninstalling the app removes it. A backup file you exported is yours to keep or delete. On a server you connected, Settings → Delete my account removes your profile there.

openGym is not directed at children under 13.

App stores

If you install openGym from Google Play or the App Store, Google or Apple handle the download and may collect data about it under their own privacy policies (for example install counts or crash statistics you allowed them to share). We can see the aggregated numbers they show developers; nothing that identifies you.

This website

opengym.ch counts page views with a self-hosted, cookieless Umami: no cookies, no cross-site tracking, no personal profile. The demo runs entirely in your browser and is never counted.

Questions

openGym is made by Duarte Santos, Switzerland. Ask in GitHub Discussions or on Discord, or write to [email protected]. The app is open source, so everything on this page can be checked in its code.