I only run open source software on my phone. However, I think there are some similar FOSS apps for Japanese on F-Droid, I'll have to take another look.
I wonder about this. Can't you just lock down the app to the point where you don't have to worry about it phoning home or accessing certain information? Or is it just ideology that's stopping you?
Not to my satisfaction, no. But I can't also install it in the first place because I don't have the Play store on my phone. Ideology is a part of it too.
