GoodHabits: 66-Day Tracker

One habit, one 66-day arc – calm, with no noise.

GoodHabits walks with you while you build a habit across a fixed arc of 66 logged days. The number comes from University College London research (Lally et al., 2010): there, the time until a new habit felt automatic was 66 days at the median – across a range of 18 to 254 days. So 66 is a reference point, not a finish line.

Why an arc instead of endless streaks:

- A manageable frame with a defined end, not a counter without a horizon
- A grace day: a missed day can be logged until the end of the following day
- Home Screen widgets – one glance is enough, and logging never opens the app
- Calm progress display that keeps your completed days visible

A good fit for:

- Morning routines and healthy habits
- Fitness and nutrition goals
- Productivity and work habits
- Mindfulness and self-care

No tracking, no analytics SDKs, no account: your data stays on your device.

If your habit still needs attention after 66 days, that is not failure – that is the spread the study actually reports.