Support.

Only at first launch — to create your account and verify your email. After that, every feature works in airplane mode. Your workouts sync to your account in the background whenever you're online.

Your training history lives on your phone and syncs to your private account so you don't lose it if your phone does. We don't sell your data, and we never share your individual workouts with advertisers. The only sharing that can ever happen is optional and off by default: if you turn on Research aggregation, we use de-identified, aggregated patterns — never your individual records — to improve the app for everyone. Leave it off, or switch it off anytime in Profile → Privacy.

An account lets your workout history survive a lost phone or a re-install, lets you export or delete your data on demand, and lets us enforce the children's-privacy age threshold required in your region. Sign up with Apple, Google, or email — you choose.

Profile → Account → Delete account. We remove your account and training history from our servers and sign you out on every device. The copy on your phone is wiped at the same step. Full instructions: /delete-account

Yes. Kettle Muscle can sync your completed strength workouts to Apple Health — it stays off until you grant permission in iOS Settings, and you can turn it off anytime. Push notifications aren't in this version yet; they're planned for a later update.