Ballon on Mapview and also want to get location whenever balloon position changed on Map in android

Recently I show the ubicabs taxi booking app. I found very nice functionality inside it. In this app they have google maps for showing markers, but they have used very good UI component for that. Also I found one more uniqueness is that whenever user moves or change the position of marker through touch it will fetch the current location. One thing that I know is that it is using the onTouchEvent of Overlay but how to create that marker balloon and how to get updated location on the basis of that marker.

I am attaching a preview of that marker here. Also would like to know that how can we scroll the text inside that balloon?

The best overlay open project I have found so far is this one, link. But it is nothing compared to the picture above. Would also like to know how they created this! Great Question and picture ;)