Hi all !
I would like to introduce you 1Sheeld ! 
Basically, 1Sheeld consists of two parts. The first part is a shield that is physically connected to your Arduino board and acts as a wireless middle-man, piping data between Arduino and any Android smartphone via Bluetooth.
The second part is a software platform and app on Android smartphones that manages the communication between our shield and your smartphone and let your choose between different available shields.
It's perfect for the developement without buying a lot of shields ! 
@+
