HTTP Live Streaming (also known as HLS) is an HTTP-based media streaming communications protocol implemented by Apple Inc. as part of its QuickTime, Safari, OS X, and iOS software. Client implementations are also available in Microsoft Edge, Firefox and some versions of Google Chrome. Support is widespread in streaming media servers. Wikipedia
The default player of Restreamer (Clappr.io) embedded in the iframe is supporting HLS streaming for iOS and Safari.