does iPad have a Gyro like the Morotola Xoom
Yes. And there are a few HUD applications that use them. However, they seem to be gimmicks more than actual, reliable HUDs. At least, the one I have here is.
First, it's actually relatively easy to upset it simply by sitting on the couch and moving the iPad above your head, rotating it etc. And it automatically centers itself when you tap anywhere on the screen, with no way to block that. So you
lose the proper HUD reference as soon as you accidently touch the iPad - not an uncommon occurance in turbulent IMC, when you need a reliable instrument most.
If you want a HUD on your iPad, there is a standalone AHRS unit out there somewhere which you can mount in the aircraft, and connect to via Wifi or Bluetooth. Never played with it, but I have seen that Air Nav Pro has support for it.