RFM Radio is an offline FM receiver for Android devices with supported Qualcomm Snapdragon radio hardware. It uses the phone's built-in FM tuner instead of streaming stations over the Internet.

Important:

Root access is required.
Android 6.0 or newer is required.
Compatibility depends on the FM hardware, vendor drivers, and firmware included by the device manufacturer or custom ROM. A Qualcomm Snapdragon processor alone does not guarantee support.
The app supports Qualcomm devices exposing either the legacy V4L2 radio interface or the newer FM HAL.
Wired headphones not required as an FM antenna.

Features:

Live FM playback without an Internet connection.
Manual tuning, hardware seek, and full-band station scanning.
Real-time signal strength and stereo/mono indicators.
RDS and RBDS metadata, including PS, RT, PTY, PI, country, and alternative frequencies when provided by the station and supported by the driver.
Europe, United States, Japan Standard, and Japan Wide tuner regions.
Favorites with custom station names, multiple lists, drag-and-drop reordering, and ZIP import/export.
Recording to 16-bit PCM WAV or MP3 at 128/192 kbit/s.
Optional five-second recording pre-roll.