Amazing item for the price, if you get one and it seems not to work - bear these points in mind - Mine arrived and I instantly popped my phone on it (Nexus 4) it slid off! Then I held it on and it just started randomly opening apps. I tried my wifes phone (nexus 5 with a rubber case) and it stuck on the slope ok and began to charge.
A bit of tinkering later I realised I had not turned NFC on, in my settings.
A further bit of fiddling and I realised the white circle on the unit had a protective plastic screen on it (like you get on a phone screen) - peel this on to reveal an extremly grippy rubber surface. The notoriously slippy Nexus 4 sticks to it like glue!!
This book is head and shoulders above any other Dinosaur book I've looked at for my junior palaeontologist. The images look fantastic and the subject of the images captures a lot of the recent discoveries and finds.
Very upto date and comprehensive guide covering a vast array of dinosaurs.