We (speakerblast) created a wake lock solution that works in iOS6 & iOS7, as our web app syncs audio across devices.

In iOS8 as of now audio playback in Safari stops when the devices sleeps and or when the user exits Safari. This is not how it was previously, rather audio played in the background and audio playback kept the device in a semi wake stage.

Were hoping this is a bug they'll fix before the final and not the new way forward.