One star off because it worked fine until now.
It is a great app and I’ve actually paid for the ad free version just so I could keep using it without the annoying ads. But today when I sat down to study I just couldn’t get the app to move on from the startup screen. It froze and I ended the task manually. Now if I keep waiting for it to do something else, it crashes. There’s no problem with my phone whatsoever. Not cool.