Simple Timestamp Add a timestamp button to YouTube comments
Watch Later - Video Bookmark Save YouTube videos for later viewing.
Watch Later - Video Bookmark Save YouTube videos for later viewing.
YouTube Bird Cute birds flying around on youtube - chrome web store
Multi-window: YouTube Multi Watch up to five YouTube videos at once
Watch Later: YouTube Manager Save YouTube videos to watch anytime with Watch Later.
OSHIStamp: YouTube Timestamps Intuitively create timestamped notes on YouTube videos.
OSHIStamp YouTube video timestamp creation support tool