Anki integration
I absolutely love Ringotan. I learned 1104 kanji (664 at Sensei) at an incredible speed, and I think it is thanks to this app. Following along the WaniKani route and adding learned Kanji to Ringotan is a lot of fun.
But I also add a lot of kanji to Anki, usually those not on WaniKani (Jouyou and JLPT), and thought about how nice it would be if I could just learn those in Ringotan as well. I believe AnkiDroid provides the facilities to do this, but I do not know how easy it is to use. But it would definitely improve my workflow.