Kakitai is a free Japanese reading & writing learning app for Windows 10 (older windows 8.1 version still available). Kakitai run on desktops, laptops, tablets, mobiles, Xbox One & hololens(untested) that are running Windows 10 but works best on systems with pen or touch screen input.
The main function of Kakitai is to help people learn to write in Japanese using handwriting recognition, Japanese writing is very complicated with learning 2 ponetic alphabets and over 2000 graphic characters that need to be learned in order to be fully literate in Japanese. Kakitai aims to help you remember this large amount of information by letting you practice characters then testing you on a selection of them. kakitai will record which you have gotten correct or incorrect then retest after a few days and once you have gotten it correct 4 times in a row it will be taking out of the potential characters for testing.
Features vary depending on device: no handing writing is available on Xbox One so everything will be multi-choice, on phone handwriting practice is available but tests will be multi-choice, printing is not available on Xbox or Phones. I am always looking to expand Kakitai and have adding most of the suggestions made by users so fell free to contact with any ideas you have to make learning Japanese easier and I will try to accommodate.