Apps on Privacy In Design

Fast Tracker

Mon, 10 Aug 2026 00:00:00 +0000

Intermittent fasting, tracked on your phone and nowhere else. Fasts, goals, streaks and history live in a local database on your device. There is no backend to hold them.

iOS, Android and Wear OS.

Join the test

iOS — TestFlight: Join the TestFlight beta
Android — Google Play open testing: Join the open test
Wear OS: installs alongside the Android build once you have joined above.

Joining the Android test needs the Google account you use on the Play Store. Apple’s TestFlight needs the TestFlight app and the email you gave Apple. Both lists are held by Apple and Google — we never see them, and there is nothing for us to add you to.

Period Vault

Mon, 10 Aug 2026 00:00:00 +0000

Menstrual cycle tracking that never leaves your phone. Fully offline, zero telemetry, and every backup encrypted with AES-256-GCM — there is no server to send one to.

iOS and Android.

Join the test

iOS — TestFlight: Join the TestFlight beta
Android — Google Play open testing: Join the open test

Why this app in particular

Period tracking is the case where “we don’t collect your data” stops being a preference and starts being a safety property. A cycle log is a record of whether someone is pregnant, trying to be, or has stopped being — and mainstream trackers have historically monetised exactly that.

Watch Cast 4 Me

Mon, 10 Aug 2026 00:00:00 +0000

Podcasts and audio on your wrist, with genuine offline playback. Download, leave your phone behind, and listen.

Apple Watch. Published on the App Store as WatchCast4Me.

Join the test

TestFlight: Join the TestFlight beta

There is no Android build. This one is watchOS-first by design, so there is no Google Play test to join.

What it does

It is a watchOS-primary player: the Watch is the device you use, not a remote control for your phone. Audio is downloaded to the Watch and plays from there, which is the part most podcast apps quietly do not do.

Wisdom Notifications

Mon, 10 Aug 2026 00:00:00 +0000

Good ideas, resurfaced. Reminders that arrive on your schedule and never leave your device — it works with the network off, because it never needed it on.

iOS and Android.

Join the test

iOS — TestFlight: Join the TestFlight beta
Android — Google Play open testing: Join the open test

What it does

Most notifications are somebody else’s idea of what should have your attention. This is the opposite: a small library of ideas worth being reminded of, surfaced on a schedule you set.