Per the GitHub readme:

This app is discontinued. The last release on Github and F-Droid will happen with the December 2024 Syncthing version. Interactions (issues, PRs) are limited now, and the entire repo will be archived after the last release. Thus all contributions are preserved for any future (re)use. The forum is still open for discussions and questions. I would kindly ask you to refrain from trying to challenge the decision or asking "why-type" questions - I wont engage with them.

The 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!

This is extremely disappointing news. I have been using the Syncthing-Fork version, but since it is based on this app, this may be the end for that app as well.