Edit: And I do wish you the best in this project! It will be nice to have something with a really polished UI for people to choose.
I see. Not being familiar with mobile app development myself I didn’t realize this was the case and it makes sense.
Well there certainly is never a plan for anyone to abandon their app. But the track record has shown a different pattern in the uh 6 years that I’ve been a Wanikani user. Perhaps it’s an unrefined and flawed opinion, but I am nonetheless of the opinion currently that any single developer application that is a 3rd party integration into a website via its API, and thus unsupported by that website, should be open source, else the likelihood of stalling and/or abandonment when it comes to keeping up with changes to that website/API, or bugs, or feature requests, massively increases.
Jakeipuu used to be my go-to app, seemed quite promising and maintained. Then that just stopped one day. No announcement or anything. And sometime last year I discovered it’s even been taken off of the Play Store. There were people willing to assist in its maintenance and development in that thread, but couldn’t due to the closed source nature. I’d rather not see another instance of this 2, 3+ years down the line.
I will get back to you on this in more detail once I have completed my pull request to Review Cache to give users an interface for importing/exporting their review cache array from/to a file. In the meantime, if you’d like to investigate yourself, you can check out the Heatmap script thread (additional links in that post, including Kumirei’s github where you can also find the Review Cache library script).