After reading this on their Android page I'm not so sure you get the whole EE game for $9.99. Seems you will be paying more after all...
Baldur's Gate: Enhanced Edition for Android Tablets contains the following enhancements: •New Adventure: The Black Pits •New Character: Dorn Il-Khan as an in-app purchase •New Character: Neera the Wild Mage as an in-app purchase •New Character: Rasaad yn Bashir •New Player Voice sets as an in-app purchase •New Player Portraits as an in-app purchase •Multiplayer support between all platforms
edit: At least with the PC version you get it all for $20... no other in-app purchases required.
Sad that they won't let you buy the game and then let you play it on what-ever OS you care to. If that were the case I would be downloading it now.