At the time, Kbin’s API was largely unfinished, meaning that technically, no Kbin instances supported apps of any kind.

Lack of a formal API to work with was tricky. There were discussions in Kbin’s development tracker about formally merging in support for apps, but it wasn’t ready for prime-time. Typically, adding a client API that’s well-rounded enough for mobile apps necessitates a lengthy checklist for requirements. Long story short, it’s a time-consuming process.

Some of the work she did -- having to drive the thing off scraping the UI, without using a kbin API -- is probably effectively being obsoleted, since kbin's API stuff is coming out now:

https://kbin.social/m/ArtemisApp/t/639282/API-to-be-unlocked-in-the-next-kbin-update

So it may be that what will happen is that existing lemmy apps will just add support for the kbin API.