I am afraid that I have to agree with the other reviews this would have been just perfect for me but as it can not be used on the Kindle Fire HD I have had to delete it glad I did not have to pay for it
The effect was just as good as I had seen on smart phones and the app moved the view around to my every change of direction. When I switched it back on again it failed to detect one of the devices needed for it to work and now it is stuck on just an overhead view that is very uninformative unless I lie down on my back to look up at the night sky.
I have seen reviews of this not working on kindle fire hd . I am using a kindle fire hd and it works great seems to calibrate quickly and is great to help educate as to where everything in the sky is . For a free app I have to give it full marks and would even say it would be worth paying for .