Privacy policy 🔒

Last updated: October 30, 2026

What is stored on your device

KinFit saves your people (names or nicknames, avatars, levels and settings), workouts, activities, badges, body measurements, chat history with Coach and progress photos in your browser's storage on your device. You can delete it at any time from Me → Erase everything on this phone. Deleting the app's website data in your browser settings also removes it.

Progress photos

Progress photos are optional and turned off by default. They are stored only on the device where you took them. They are never uploaded, never included in sync and never sent to Coach.

Backup & sync

To stop workouts being lost when a browser is cleared, backup is turned on automatically when you first set up the app. You can turn it off any time in Me → Backup & sync. When it's on, a copy of your people, settings, workouts, activities and body measurements (not photos) is stored on Cloudflare's servers so you can restore it, or use it on other devices, with your private recovery code. The data is stored under a scrambled (hashed) version of your code, so the code itself isn't saved on our servers. Your phone can save the code in its password manager. Anyone who has your recovery code can see and change that data, so keep it private. You can delete the cloud copy at any time from Me → Delete the cloud copy.

Coach (AI answers)

When you ask Coach a question it can't answer from its built-in tips, your question, the recent chat, your level and a short summary of your recent workouts are sent to Cloudflare Workers AI to create an answer. They are not used for advertising, and this app doesn't keep them on its servers. Parents can turn off AI answers for each person in Me → Parent controls.

Limits and logs

To stop the free AI and sync allowances being used up, the app keeps a count of requests for each internet (IP) address for up to one day. Cloudflare, which hosts the app, may keep standard technical logs to keep the service secure. If the site owner turns on Cloudflare Web Analytics, it counts visits without cookies and without identifying you.

Backup history

While backup is on, the server also keeps one copy per day of your backup for 30 days, so you can undo mistakes with Me → Restore an earlier backup. Deleting the cloud copy also deletes these daily copies.

Feedback and error reports

If you send feedback, your message (and an email address, only if you choose to add one) is kept for up to 180 days so the site owner can read it. When something breaks in the app, a short technical error report is sent automatically: the error message, which part of the app, the app version and the type of device (for example "iPhone"). It contains no names, workouts or other personal details and is kept for 30 days.

Workout reminders

Reminders are added to your own phone's calendar. The app doesn't store your reminder times on its servers.

Kids and families

KinFit is made for families. Children should use it with a parent or guardian, who can set a parent PIN to stop changes to levels, people, sync, body tracking, Coach settings and data. Please use a first name or nickname rather than a full name. Coach gives general fitness tips, not medical advice.

Changes and contact

If this policy changes, the new version will be posted here with a new date. Questions? Contact the site owner through the project's GitHub page.