Announcement by the creator: https://forum.syncthing.net/t/discontinuing-syncthing-android/23002
Unfortunately I don’t have good news on the state of the android app: I am retiring it. The last release on Github and F-Droid will happen with the December 2024 Syncthing version.
Reason is a combination of Google making Play publishing something between hard and impossible and no active maintenance. The app saw no significant development for a long time and without Play releases I do no longer see enough benefit and/or have enough motivation to keep up the ongoing maintenance an app requires even without doing much, if any, changes.
Thanks a lot to everyone who ever contributed to this app!
What is this alternative of which you speak?
Syncthing-fork. Both show if you search for Syncthing in fdroid. Since imsodin seems to be OP Dev maintainer for Syncthing, i think he is referring to the fork.