I’ve used this app for about 9 years now from when I first started learning Japanese. The fact that it is free and still running is impressive in itself. I frequently use it throughout my everyday and I have hundreds to thousands of points saved. I love the format and UI of their “lists” feature and study feature. I DO genuinely get scared every once in a while of somehow losing my data on this app and my 8-9 years of history of what I have learned.