Every product designer has been trained to optimize for time-in-app.
More sessions. Longer sessions. Red badge notifications at 9:00 PM reminding you that your imaginary streak is about to reset. In consumer software, attention is treated as an infinite resource to be mined.
The result is predictable: exhaustion and abandonment.
Ask any physiotherapist how many patients complete their home exercise regimens. The answer is close to zero. Patients receive an intimidating sheet of twelve complex biomechanical routines, do them twice, feel overwhelmed, and quit entirely.
Good software does not demand residence in your life. It arrives, solves the friction in fifteen minutes, and gives your day back.
When I designed the rehabilitation engine for kinē, we set an uncompromising constraint: the progressive plan (Calm → Load → Capacity) had to be hard-capped at fifteen minutes a day. No marathon workouts. No clinical guilt. Just enough stimulus to signal recovery, then close the tab.
We applied the exact same constraint to Provia for pharmacy exams and Bodhi Pomodoro for desktop focus. Bounded sprints. A small ritual. Then done.
When an app promises that using it won’t consume your entire evening, you actually open it tomorrow.