If you want to switch because of the ban in the US, you’ll probably be able to get around that by sideloading it or using a vpn.
You could also look at the linktrees for anyone you follow on tiktok to see where else they have accounts. A lot of people post the same content to multiple platforms.
Loops looks promising. It doesn’t have the source code available yet, but Dan’s said he’s going to release it under AGPL.
There’s also Vidzy. They have federation working, but it’s is only in the browser so far, isn’t as polished, and has barely any users.
Have they been using AI art? All of their art that I’ve noticed has been from David Revoy.
And it’s a fairly small open source project that only started working on the phone app last year. It’s not that surprising they haven’t gotten apps for every platform yet.