Halfday is a fasting timer for people who want to eat in a window, not join a program. Two taps to start. A ring that fills, with fasting stages marked on it, ketosis included. Forgiving streaks that survive one busy day. A weight trend line. No ads, no quiz funnel, no AI coach. Timer, stages, streaks and weight log are free forever. Plus ($29.99/yr) adds full history, journaling, custom durations and CSV export. Android today. iOS is in review.