This is the Android app I've been using that has helped me more than any other app or forum or any other resource - https://play.google.com/store/apps/details?id=com.nwalex.med... (I am not associated with this app at all, I'm just linking because it's helped me so much).

The real win with it is that you can place a widget on your homescreen with 1) the number of days in a row you've reached your daily-duration goals, and 2) your all-time best chain. So simple but so effective.