Over on YouTube Double A Labs has posted a new video demonstrating how to use an RTL-SDR and Android device to receive broadcast FM stations, and to decode any associated RDS data.
In the video Double A uses the SDR Touch Android app and the Advanced RDS function to show the RDS information. He goes on to explain the various pieces of information RDS data provides including clock time, active RDS groups and alternative frequencies.
Tune broadcast FM radio and decode Radio Data System (RDS) information using your Android phone and an RTL-SDR USB (see parts list below). RDS can include station identification, song name, the current time for a receiver to sync its clock, alternative frequencies the same program is on, and more!