YouTube
Allows searches by location for geotagged YouTube videos.
Allows you to reverse image search the automatically generated thumbnails for a YouTube video. Also shows you the time the video was uploaded.
(The time function currently has a problem where it is failing to identify a video that is set as Private or Unlisted. If the video is later set to Public, Data Viewer is incorrectly showing the time this happened as the upload time.)
Collaborative platform for groups working on verification of YouTube videos
Collects all of the comments on a selected YouTube video
The two below are largely unnecessary now that YouTube has once again made it possible to use the keyboard for frame-by-frame viewing (Use the . key to go forward and the , key to go back)
Allows you to speed up, slow down or advance YouTube or Vimeo video frame by frame within the browser. By Calum Eadie
Allows video from YouTube or Vimeo to be played frame by frame or in slow motion