Tiny rss is an open source RSS feed reader project that you can install on your own server . It’s very similar to Google Reader with all it’s features nad eye candy (even more!), and also integrates a filtering system to tag and categorize articles. If you want to get off Google (Reader)’s grip, that’s a good start :)

Convert web pages into professionally looking RSS feeds

This is a service to convert any RSS feed into an account that Mastodon (or any other ActivityPub social network) can subscribe to.