Well, the app is obviously working for some folks, but in my case it's junk. 13" MBA 2012 OS X 10.10.1 connecting with iPad Mini Retina or iPhone 5s (both iOS 8.1.2) using genuine Apple Lightning cable and direction connection (i.e. no USB hub). Most of the time the iOS app never gets beyond the "Connect to Mac" stage, even though the screen flashes on the Mac indicating new display hardware is available. Sometimes the iOS app gets to the "Launching Duet…" and hangs. Rarely, the iOS app actually becomes a display; however, when that happens my mouse is frozen (in a "stuttering" sort of way). Waste of good money for me.