A training practice for sustained attention — the kind of focus that holds when nothing about the task is rewarding you for staying with it.

In development for Android. Not yet available.

A dual-task training exercise. A breath practice. And a periodic check-in assessment. The design and the progression come from published research in the field — including the parts of it that do not support any of this.

Length is programmed, like weight on a bar

You don't pick the load. It's prescribed, it goes up as you train, and it backs off before it climbs again. That is what separates training from a habit.

It requires focus, even when it gets dull. That's the load.

The last few reps are the ones that count, and you already know this about everything else you've trained.

Two numbers to track your progress

Slips and steadiness, in plain words. No composite score, no streaks, no confetti, and nothing that rewards you every ten seconds — those are the mechanics that took your attention in the first place.

No account. No email address. Ever.

No sign-up, no name, no advertising, no tracking of any kind, and no third party receiving anything. Sessions are written to your phone first, so a bad connection can never cost you one. Delete everything, from the phone and from our servers, in one tap in Settings.

How the three parts are built, and which published papers each parameter came from.

Whetstone is not a medical device, and nothing in it is medical advice. If your concentration genuinely worries you, that's a conversation for a doctor. For adults, 18+.

Attention isn't something you fix. It's something you keep.

Last written .