Notify only on player stop / mark as watched

Hi there,
I’m building an addon for a movie and tv shows watch list app called Flox and I’m trying to notify the user that the item was marked as seen. I’m using `xbmc.Monitor` with `xbmc.Player()` and `progress` but the user will see a notification when the progress time is bigger than 80%.
Is it possible to listen to user action just like Player.stop or when Kodi considers an item as watched?
Thanks for your help.