I actually bought 2 of these when I realised that the Nexus 7 2013 has QI charging along with my Nexus 4
The device is about the size of a coaster and a smart matt black colour.
there is a LED on the side which lights up orange when a device is placed on the pad and turns green when charging.
It turns off when not connected and when charged.
The light is not too bright so you can have this by your bed and it won't keep you awake/
As for charging - you have to place the phone slightly to one side for charging, which is about the same as plugging it in to the mains, ok possibly slightly longer.
The big advantage is that there are no leads to tangle and the connection plug does not get scratched.