Try the app in Chrome, which uses HTML5 audio. Flash is for other browsers with graceful fallback.
As Firefox and other browsers support and stabilize HTML5 audio a.k.a. WebRTC, this App will support it too.
As Firefox and other browsers support and stabilize HTML5 audio a.k.a. WebRTC, this App will support it too.
WebRTC stands for Real Time Communication, and is a protocol for allowing browser-to-browser traffic. HTML5 Audio is a spec for playing sound through the browser via <audio> tags, which is confusingly also distinct from the Web Audio API, which is a Javascript API for programmatic sound.