Scribbler is a full-featured information retrieval system that lets you quickly find the key points in podcasts and YouTube videos. It offers AI-generated summaries, full transcripts with timestamp navigation and a natural language search interface. It also has a conversational interface and offers free and premium subscriptions.
Last, Summarize.ing offers immediate and accurate summaries of YouTube videos using the Claude2 AI technology. It offers full summaries, highlights, mind maps and segmented summaries, so it's good for quickly absorbing a lot of information. The service is free for general use, though premium plans will be available for heavy use.