ILS is a browser extension that colorizes issue and PR links to see their status (open, closed, merged). It uses GraphQL to make a single HTTP request to check all the links on a page at once. This means that you'll need to create a API token and add it to the Options page or else the extension will not work.
GitHub Enterprise is also supported. More info in the options.
- Refined GitHub - Browser extension that simplifies the GitHub interface and adds useful features