Sadly, this project has been abandoned for over 3 years now. Since then Syncthing's API has changed and as a result several features of this app are broken. Some finessing is required to get it to interact with a preexisting Syncthing install at all, as it tries to load/create Syncthing config files at an incorrect directory and uses the wrong port for the web API. Integration with Nemo (Mint 22 Cinnamon's file explorer) is also entirely broken. I have found
Using Linux Mint 21.3, this version works fine but if you leave it running for a long time it starts to use too much RAM, I got to use up to 3GiB and the PC started to run too slow when using swap because the syncthing-gtk had used all the available ram. I had to uninstall it, it's a pity because I found the integrated notifications useful.