Each app is checked independently the moment this page loads — a slow or down app never holds up the others. Nothing here is saved to history.
Each app is checked the moment this page loads, at two points — directly inside the server, and over the public internet. The worse of the two sets the colour:
A behaviour line (on apps that have one) is not a live check — it's the last 24 hours of browser tests: all passed, a failure, all failed, none run.