I wrote this app a couple of years ago to practice Japanese which I was studying at the time. It was initially made with Silverlight, but later ported to Unity and deployed to iOS, Android and Windows Phone and sold on respective market-place. It is currently only available for Android. A demo (WebAssembly) can be found on the link below. I also made versions for English, Swedish, Devanagari (Hindi) and Tengwar (Tolkien) but they are not on any store at the moment.