Show 'watched' status for watched videos

[stackingflow]

Issue

• Sometimes the videos we have already watched are recommended to us again in our home feed.
• Its hard to distinguished the video we have already watched.

Solution
Show a watched tag (text inside a box) on the top left of the video.

[oSumAtrIX]

Would require a local database, but nice idea

[TheJeterLP]

Wouldn't appear as watched if I watch a video on another device/client, so in my opinion not possible to do.

[LisoUseInAIKyrios]

YT now shows this as a seekbar in the thumbnail.