Most apps on the list are lemmy apps, meaning they don't work with kbin. Artemis is specifically designed to work with kbin, not sure if or when any of the other ones will go in that direction or become interoperable as there are some challenges with the kbin API at the moment. Having said that, a new API is in the works (https://codeberg.org/Kbin/kbin-core/pulls/357) so things should get better with time. Some of the apps are in very early stage of development so it may happen that they adjust OS availability and platform support.
Same here and today the Mlem app has disappeared from my TestFlight list. Another thing worth noting is that Memmy works on my iPad mini. Mlem doesn’t. At least not correctly.
The main dev was harrassed off of the project, basically. He said he passed the source code on and it should be coming back to test flight under a different link soon, theoretically.
It seems he was the dev who initiated the project, but hasn’t been the main contributor for a while. He’s handed it over to the other devs contributing, who weren’t aware of what was going on or that he was planning to leave and it sounds like they’ll be back on track in the next few days.