v1.33.3 Changelog:

• Watched videos feature will now only work in feeds (and nowhere else).
• Added option to add/remove videos from/to watched videos (only possible in subscriptions page using YouTube Center's grid atm).
• Fixed comment flags not showing in older versions of Opera (why do you not support MutationObservers?!).
• Fixed YouTube Center buttons not appearing when you visit a video for the first time.
• Fixed storage bug. It will now save the settings correctly again.
• Fixed bugs...