Is there a public 3rd party GitHub status monitor?

When I access GitHub and get an error, I'm often unsure whether it's because of issues with my connection or because GitHub is genuinely not working and hasn't updated its status page.

Is there an existing third party GitHub status page with a higher resolution than the official GitHub status page? I'm asking here because discussions about GitHub uptime are popular and I hope someone has already found a solution.

Let's keep this thread about high resolution status monitoring instead of GitHub uptime, we've had a lot of the latter already, e.g. https://news.ycombinator.com/item?id=22763270 .