Fraidycat or Fraidyc.at is a browser extension for Firefox or Chrome that lets you follow people, see a summary of who has recently posted instead of a news feed, and expand the summaries to see recent titles/excerpts. It was created by Kicks Condor. Use it to follow people (hundreds) on whatever platform they choose — Twitter, a blog, YouTube, even on a public TiddlyWiki.
Twitter, Instagram, SoundCloud. These sites don't support RSS, so Fraidycat does its best to pick things out of their web pages.
Pinboard, YouTube and Reddit. These sites do offer RSS, but it's not advertised very well. So Fraidycat figures out where to find the RSS feeds for you.
TiddlyWiki. Fraidycat reads the whole wiki and treats it like a giant RSS feed. Be aware that giant wikis may load down Fraidycat.