My Grand daughter sticks it up in every room. Shower, back of a music stand, fridge, patio door window just to list a few. Like others have said it should be a smooth surface and moisture is helpful as is on any suction cup.
It appears that after you remove the suction cup, the mounting would receive a hook. If you wish to add a hook to the speaker itself, I would suggest an "S" hook like those used for hanging plants. Some modification to the "S" hook would probably be necessary.
I use an android device and yes it works. Basically there's two forms of bluetooth connectivity : phone only and phone and audio. The audio buttons on the speaker interface with the same buttons on android apps (pandora, music player, etc).
You can even stream youtube audio or Netflix audio through it..
And the same skip controls work.
I only have the pink one myself, but it does not appear that there is any mechanical difference. Prices may vary because of demand, availability, or because they are being carried by different sellers.