If you are learning Japanese but you don't know how to read the Japanese Kanji,You can enter Japanese Kanji in Handwriting keyboard, then get the hiragana.
Ofcourse, you can Copy and Paste original text,App can auto return the best ruby.

*In order to input by handwriting it is necessary to add a handwriting input keyboard.You can check the help in this App to know how to add the Keyboard.