FocusBottle is an Android focus-companion app that turns focus timing into a visible, collectible experience. While you focus, light particles inside a bottle dance and evolve with your level of concentration; when a session ends, every stretch of time is gathered, recorded, and visualized on a calendar heatmap.

What makes it different from standard Pomodoro timers:
- Light Particle System — particles become more active as you focus; the bottle evolves through 4 stages (Glass → Crystal → Starlight → Aurora) up to Lv.79
- Pomodoro timer — 25/50/90 min modes with interruption detection, pause/resume, auto-save
- Focus calendar — monthly stats plus streak tracking with heatmap
- Task management — priorities, due dates, pomodoro binding
- White noise — Rain, Ocean, Cafe, Wind
- Share cards — This Session / Streak / Milestone / Daily Summary
- Achievement system — 5 tiers, 2 XP per focused minute

Free, works fully offline, no sign-up required for core features. Optional in-app purchases for skins.