Ultradian Timer

You are not bad at focusing. You are working against a rhythm you cannot feel. Attention runs in waves of roughly ninety minutes — rising, then a dip where concentration, memory and motivation all fade. Ultradian Timer helps you work with that rhythm: an activity cycle, then a rest cycle, then round again, for as long as your day lasts. It does that one thing. It will not organise your tasks, score your day, or tell you that you did badly. THE GONG A sound marks every boundary, and it reaches you through a silenced phone, through Do Not Disturb, with the screen locked and the app closed — even after you have force-quit it. Sixty-eight to choose from: bells, singing bowls, hand drums, birdsong, and longer melodic pieces. Or bring your own. Every one can be heard before you choose it. THE LENGTHS Ninety and thirty to begin with, or 75/33, or 60/20, or whatever you set. A single cycle can be made longer or shorter without changing the setting, so an afternoon that needs forty minutes does not become a new rule. Working hours stop the loop from starting a cycle at three in the morning. A cycle already under way always finishes. IF THE APP CLOSES Every cycle is recorded as an event and the state is replayed from those events, so closing the app, restarting the phone or having it killed by the system costs nothing. The clock is never guessed at. YOUR DATA No account, no server, no analytics. The app never asks for the internet. Nothing is collected, so there is nothing to opt out of. Your cycles are a file on your phone — export them as a spreadsheet, or erase them. Completed rest cycles can optionally be written to Apple Health as mindful minutes. Activity cycles are never shared. ALSO IN IT • A home-screen widget that keeps counting with the app closed • Siri: start, rest, pause, resume, stop • Control Centre, the Lock Screen and the Action button • Statistics that describe rather than judge — totals, when your cycles happen, and the balance between activity and rest. No streaks, no targets, nothing to fail • A history you can edit, including cycles you did away from the phone • Two optional eye practices, offered at a boundary and never required • VoiceOver and Reduce Motion throughout THE SCIENCE The About screen explains where the ninety-minute idea comes from — Nathaniel Kleitman's Basic Rest-Activity Cycle — and is honest about what has been measured and what is only proposed. Every source is listed and linked. Where the evidence is thin, it says so. Requires iOS 26.