Like GNU Radio, this module uses master and next branches, which are supposed to be used with the corresponding GNU Radio branches. I recommend staying up-to-date by using the next branch.
GNU Radio v3.7.X or the v3.8 development branch (next).
See the GNU Radio Wiki for installation instructions.
Software from your package manager. For Ubuntu systems, it's
sudo apt-get install cmake libboost-all-dev liblog4cpp5-dev swig
mkdir build cd build cmake .. make sudo make install sudo ldconfig
open apps/rds_rx.grc example flow graph in GNU Radio Companion.
Quick example: http://www.youtube.com/watch?v=05i9C5lhorY
HAK5 episode (including installation): http://www.youtube.com/watch?v=ukhrIl4JHbw
FOSDEM'15 talk (video and slides): https://archive.fosdem.org/2015/schedule/event/sdr_rds_tmc/