UnlockHabit is a completely free, offline-first habit tracker for iPhone. Build streaks, track daily habits with heatmaps and reminders, and follow guided programs — all stored privately on your device. Zero data collection, no account, no cloud. It works fully in airplane mode because it never goes online. Focused and clutter-free: Streak Freeze, completion heatmaps, gentle per-habit reminders, and weekly insights. iPhone (iOS 16+) today; Android in development.