While working on tasks I caught myself wondering when did I start .. and "isn't this task taking too much time?".
So something you probably have already though about but adding a countdown timer per task and recording how much time is spent on the task. Maybe the timer could be visible constantly to remind you not to get distracted?

If you consider this useful I am happy to collaborate :)

P.S. This is a great app which I have been using just a day and enjoy a lot! Even considered doing it by myself in the past but I'm glad you already did it!