Just to throw this one in:
Carpe Iter Pad. - As they write on their website, the actual Android is on the way.
There is a BT solution for your handlebars. Often sold with the mentioned Carpe Iter. I bet, you can use them with the Galaxy, too.
Just google "Carpe Iter controller".
I want to ride some ACTs and TETs. Therefore I decided to buy this one. - Lets see, how it does on the route.