How do I install it on Android?

1. Open dayline.online in Chrome (not inside another app’s browser: Google blocks sign-in there).
2. Sign in with Google, create a passkey with your fingerprint or screen lock, and save your recovery key.
3. Tap Chrome’s menu (⋮) → Install app (or Add to Home screen). Dayline opens in its own window with its own icon.
4. Optional: in Settings › Reminders, switch on notifications (reminders and due tasks; a morning brief or an evening recap under More options if you like). Long-press the icon for Log something and Remind me, and share text from any app into Dayline.

It’s a web app, so there’s nothing to download from a store, and updates arrive by themselves.