For all prior versions of iOS, I've used the itms-services:// URL to install test iOS apps over the air (OTA). Now, all my devices with iOS8 fail when trying to install apps using this approach. Example URL:
itms-services://?action=download-manifest&url=https://myWebsite/myApp/myApp.plist
Summary of problem:
This seems to be a bug in the Beta5 and GM versions of iOS8.
Over at Buildozer we've found a workaround: change the bundle identifier of the app in the manifest file. (More details: https://buildozer.io/ios8)
A workaround that doesn't involve changing the manifest files is to restore the entire device from backup, however we feel the manifest 'hack' is less disruptive to users.