GoodHabits: 66-Day Tracker

New in 3.0: interactive widgets, a grace day for missed logs, and reminders you can check off right from the notification. No tracking — your data stays on your device.

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.