90 Minute Timer
Set for 90 minutes. Press start — it rings when the time is up.
Free from Ticka — the reminder app that rings like an alarm, even on silent. Close this tab and the timer stops. On your phone, Ticka rings even on silent. App Store → Google Play → App Store → Google Play →
This timer runs while the tab is open. If you need it to go off when your phone is in your pocket — that part needs the app.
The ninety-minute cycle
Sleep runs in cycles of roughly ninety minutes, and the same rhythm shows up when you’re awake: attention climbs, holds, and then drops off whether you agreed to it or not.
Ninety minutes is long enough to finish something real and short enough that you can see the end from the start. What matters more than the number is the break after it — the cycle only works if it actually closes.
If the ninety minutes are a full sleep cycle rather than work, the nap timer adds time to fall asleep and wakes you gently.