Tap the Download OnlyReminders button above (or scan the QR code with your camera and open the link it shows).
Your phone will save a file. You'll usually see it appear at the bottom of the screen, or in a "Downloads" notification — tap it to open.
Step 2 — Your phone will warn you first. This is normal.
Because this app isn't from the Play Store, your phone will show a warning like "For your security, your phone is not allowed to install unknown apps from this source."
Tap Settings on that warning, then turn on Allow from this source.
Go back (the back arrow) and open the downloaded file again.
You may see one more screen saying something like "Play Protect doesn't recognize this app" — this happens with any app not from the Play Store. Tap Install anyway.
This app is safe — it's built and sent to you directly, not something random from the internet. These warnings appear for every app installed this way, not just this one.
Step 3 — Install and open
Tap Install. It takes a few seconds.
Tap Open once it's done — or find OnlyReminders on your home screen / app drawer.
The app will ask permission to use your microphone (so it can hear your reminders) and to send notifications (so it can alert you). Tap Allow for both.