And somehow Pokemon Go is down, too. They use GCP for hosting, but I'm not seeing other outages on GCP. Maybe they have deeper integration with Google's Cloud than publicly disclosed?
Discord was sort of down (wouldn't load), but I could log in again a few minutes later and everything was OK. My company's product is hosted on GCP and there are no problems that I can detect without administrative access (which I can't obtain because it's behind a Google login); services are returning correct results.
Google Maps for sure, maybe some GCP as well (as console is down, Discord and Playstation Network as well are having issues - which seems like some GCP service)