People that stacked Zero
Full disclosure, I'm on the board and we (True Ventures) are an investor. This app has played a huge role in resetting my overall health. I've used it daily for nearly 2 years and it's effectiveness is significant. Beautiful, simple interface + effective results = good habits.
Good Apple Watch complication, very intuitive. iPhone app is super informative. App allows you to start fast and change the time in case you actually fasted earlier than when you hit start. Calculates time spent fasting vs not fasting.