Apps you use to study japanese

Check the big Resources list

I like TangoRisto to practice reading (it’s free) but Satori Reader wasn’t bad when I used the free beta.

For grammar you can try the (paid) Human Japanese apps, which dispite one being called intermediate really only cover elementary level. I’ve not seen one that covers a Tobira equivalent yet. Of course there’s plenty of good YouTube channels that cover grammar like Misa, Nihongo no mori, Cure dolly, etc and Tae Kim’s Grammer guide is free online.

There are also several courses on Memrise as well.