One thing I'd like for the fasting feature, is the ability to make it open ended, or at least not stop counting once the planned end time is reached. I tend to do it a bit more "ad hoc" where I don't always do the same time frame each day, so it'd be nice to just have like a start/stop button. Right now I'm using a work around where I just set it at like 11PM, then stop it manually when I'm going to eat.
Another thing that may be nice would be for it to display on the diary for that day once the fast is marked complete. I know you can view it in reports, but it's kind of buried otherwise.