It's not exclusive to NixOS, but I've only packaged it for NixOS.
The UI looks like shit, but it allows showing all the configs in /etc/wireguard and toggling them on or off with wg-quick.
The biggest issue I had was with slint. I can't make sense of it (yet).
This was written because after getting a windscribe subscription, I found out that the app doesn't work on #NixOS and the pull request to add it 1) doesn't work, 2) is being nitpicked to death.
I didn't want any browser + Rust solution (bloated) --> no Tauri, no electron, no webkit, no QML (that's also webkit, isn't it?)
Didn't want immediate mode - just not convinced by it --> no egui and all that other stuff
Wanted to click together a UI and not fight too much with C++ bindings --> GTK4 got rid of their WYSIWYG editor, Qt creator doesn't do Rust AFAIK, and all Qt bindings seemed like a lot of work getting it to run
Slint just seemed like the best thing I could get running under an hour, given those conditions.
If you can think of something else that fits better given those criteria, I'd be happy to check it out.