Is there a simple GUI application that will monitor running processes periodically and alert the user when a process is not running? The ones I have found are far too complex (eg Monit). I am sure this is trivial to achieve with a script, but I'd rather use a GUI.

A use case would look like this: every 60 minutes check if Syncthing is running and display a notification if it's not. In my experience, Syncthing is very reliable when it launches successfully but there may be an issue with conflicting versions that may prevent it from running at boot. Syncthing has no way to alert the GUI user when something goes wrong and you may find after you left home that your laptop hasn't synced. Checking manually is a headache, prone to errors and goes against the idea of fit and forget.

(Debian Trixie with KDE Plasma)