Yes. It's completely free and open-source. It's a result of many efforts during last two years.
Just unzipping the archive file in library folder present in the Arduino's root folder.
In this first step you can report an issue using the issue-platform of the Google Code site where the project is currently hosted.
After you will be able to report your experience in a forum dedicated to this library.
This library is developed using GSM/GPRS & GPS Shield of Open-Electronics.org and futurashop.it.
We're working in order to make this library compatible with the TiDiGino board.
Other shield are not ufficially supported.
To switch between the two board you should comment and decomment appropriately the lines 2 and 3 in HWSerial.cpp.
Just decomment the line DEBUG_ON in GSM.h and reupload the code.
In this case use the forum to report your experience.