[Edit: The GitHub repos are called "syncthing-android". The Android apps are called "Syncthing-Fork" or "Syncthing-Fork Wrapper", which adds to the confusion.]
If I recall, there used to be a syncthing-android app on Google PlayStore. That was discontinued by @imsodin in Oct 2024 (https://forum.syncthing.net/t/discontinuing-syncthing-androi...).
There was a version of sycnthing-android on F-Droid. I don't remember who maintained that. I have version 1.30.0.4 installed. But I cannot find any information about that version anymore.
The current version on F-Droid is 2.0.12.1. That seems to be maintained by a fellow named @researchxxl. Apparently @researchxxl claims to have inherited the source code and signing keys from a person named @Catfriend1 (Not sure who that is, the maintainer of version 1.30.0.4?)
There is another fellow named @nel0x who seems to be maintaining a different version of synchthing-android? (Edit: Here it is, https://github.com/nel0x/syncthing-android, which says that it is a fork of the one maintained by @Catfriend1).
Can confirm same case here. App was installed from f-droid, no longer linked to the store.