It is too easy to star a project on GitHub, maybe because you consider it is a fun experiment or because it actually matters to you. However, keeping track about updates (say about repositories your project depends on), is harder. You can watch a repo, but then you’ll also be subscribed to all the clutter that sometimes issues and PRs cause.
Sibbell is a service that, once connected to your GitHub account, will sync your starred repos, and then, it will automatically check for new releases or tags on those repositories. Whenever one of your starred repositories gets a new release, you’ll receive a notification on your e-mail.
Free tier allows you to receive updates on your starred repositories as they happen; paid tier allows you to digest those updates into a single mail per day or week, and disable starred repositories you are not interested in knowing about.