It's an alarm & timer app with no sound & only vibration.
All features are completely free to use.

Features:
- Quick start-up, comfortable operability
- Any number of preset alarms and timers
- Repeat alarm setting (day of the week can be selected)
- Time designation timer, countdown timer, color setting
- Vibration notification while the app is running
- Background notifications, number of notifications displayed on icon badge
- Dark mode
- All free

URL scheme:
vibration://