Here is a schematics of audio cable connecting Samsung SIII to Kenwood/Baofeng/Wouxun or other compatible radio.
Samsung SIII uses four pin 3.5 mm TRRX connector that differs than standard TRRX.
This cable can be used for APRS/Packet Radio. Most popular program for this purpose is APRSDroid. ALso can be used for Echolink, audio recordings, or similar usage.
You have to adjust volume output on both Samsung phone and radio to avoid distortions. Cell phone cannot control PTT of radio so you have to turn on VOX on radio to enable triggering TX when signal should be transmitted.