Hey,
I still wish this is also is an option on the website. It’s still take some extra steps to mark multiple episodes as watched. Especially with shows with more than 50 episodes in a season.
You have to mark multiple episodes as watched.
The app now has a function when you mark an episode as watched that it asks if you want to mark the previous episodes as watched too like the iOS app also has now:
http://forums.trakt.tv/t/feature-request-marking-previous-episodes-as-watched/3021/6
Greetings!