Great accessory for ipod/ iphone. comes with multiple parts so most idevices are covered. The actual phone holder part is very study so i had no worries it would fall out or scratch my phone. It works by touching the screen icons (shoot buttons) with two little levers on the gun that are moved forwards and back by the triggers. The levers have little foam circles on the end so it will not damage the touch screen on your idevice.
Build quality is good, it doesn't feel like it would break and it is entirely made out of plastic. The end of the gun will also unclip to make the gun smaller based on preference. At the moment their is one free game available to download called alien attack which is quite fun and works well with the appblaster. You can also try out the app first to see if you like it because it is playable without the gun. (The app has not been updated to make use of the retina display).
My only negative is that alien attack at the moment is the only FREE game available that works with the appblaster. There is also another game which is around 1.50p that works with this gun. It would be nice if apptoyz could develop more games as essentially you are paying 15 pounds for one game. Despite that its a great little accessory and well worth a try.