iViewer can show video streams direct from IP cameras and DVRs. But only specific stream profiles are supported on iOS (Apple devices).
MJPEG is always supported - you should be able to view any MJPEG stream directly in iViewer.
To learn how to insert a video into your GUI see the Video Tool page.
But for live streams in traditional video formats, iOS Devices support only specific video stream codecs. Please see the below URL for detailed information:
Apple iOS Video Formats.
More info on HTTP Live Streaming for iOS: https://developer.apple.com/library/ios/documentation/networkinginternet/conceptual/streamingmediaguide/FrequentlyAskedQuestions/FrequentlyAskedQuestions.html
iViewer for Android currently supports MJPEG and H.264 video formats.