Hey guys, yeah it’s a lot of fun and works basically the same way as many other sites based on spaced repetition system algorithms like Kanji Koohii RTK or Smart.fm (iKnow) and Anki. However it gives you a really nice interface with full audio and it has a cute little garden visualisation which is basic atm but cute and I could definitely see it updating. Also it’s free unlike iKnow now.
Keep in mind it’s still in beta and many courses are still being worked on. I can’t say for other authors, but the problems I had with the N5 course are already fixed :P