If you frequently use WebPageTest or similar services for checking page performance, or just like to keep track of things like CSS size or JavaScript size, you’ll probably want to try this.

SpeedTracker is a tool for using the WebPageTest API to do automated runs. It’s free and open-source; and it has a really clever implementation using GitHub Pages. You can even set up performance alerts via e-mail or Slack so you don’t accidentally blow up your JS bundle size without noticing.