The first of those small tools we mentioned is out in the wild.
TooMuchYouTube is a Chrome extension that sets YouTube's playback speed automatically, based on rules you define. Match by channel, by words in the title, or by video ID, pick a speed between 0.25x and 4x, and let the extension do the rest. First matching rule wins, and a manual speed change always takes priority, so it stays out of your way when you want it to.
It scratches a very particular itch: tutorials that linger, podcast intros you have heard a hundred times, and lectures that are excellent but unhurried. Rather than reaching for the speed control on every video, you teach it your preferences once.
It is free, open source under GPLv3, and available now on the Chrome Web Store. Source, issues, and the changelog live on GitHub — bug reports and suggestions are very welcome.
More small things to follow.