https://zombo.com !!

I used to work on a CEF (Chromium Embedded Framework) integration for an in-house multimedia platform that was kind of like a game engine with distributed real-time rendering. We used https://html5zombo.com routinely to smoke-test: the animation and audio together made it easy to tell when machines were getting out of sync, or when we weren't pushing frames fast enough, or when the audio was broken (as pulseaudio and CEF version updates would often do). Good times.

Oh but reaching zombo.com is only the beginning. You can do anything on zombo.com!