SDR Touch is an Android app which allows the rtl-sdr dongle to be used on an Android device. A USB OTG (on-the-go) cable is required to connect the android device to the tv dongle. The blurb on the app authors website reads
(SDR Touch) Turns your mobile phone or tablet into an affordable and portable software defined radio scanner. Allows you to listen to live on air FM radio stations, weather reports, police, fire department and emergency stations, taxi traffic, airplane communications, audio of analogue TV broadcasts, HAM radio amateurs, digital broadcasts and many more! Depending on the hardware used, its radio frequency coverage could span between 50 MHz and 2.2 GHz. It currently demodulates WFM, AM, NFM, USB, LSB, DSB, CWU and CLW signals.