Temper your expectations, and you wont be disappointed
I use this all the time for my iTunes mini player, so I can glance over and see whats playing. To those intending to use this for video, keep in mind what this app is -- its a monitor connected via wifi. Its never going to be as responsive as a monitor on a wire. Lag is inevitable. If you plan to use this as an easy way to have a dedicated screen for iTunes, a diagnostic display (e.g., Activity Monitor), or something else where the update frequency is reasonable, you wont be disappointed. Works great between a Yosemite desktop and an older iOS 7.1 iPad 2.
JG401 about
iDisplay, v3.2.0