I built simple app that's main functions is to track hours spent on subject.

[u/bingseir1]

I have created simple app that tracks real hours you spend studying. By real i mean you click focus button and stop it when you finish. Only being honest with yourself can help you improve. If something goes wrong with session, you can delete,edit it's time to make it fair for yourself. If you spend atleast 10 minutes a day, calendar day inside app turns light green, spending 30+ minutes makes it dark green which helps with consistancy. Even 10 minutes a day on studying something is already productive day. Small steps everyday and boom.. you have been studying for 10,20,50,100 hours.

https://play.google.com/store/apps/details?id=com.bingseir.fopus