I want to know how to implement FM Transmitter in android app. I want my android phone generate a radio frequency. So that I can play music on my phone and transmit it over radio frequency for a near by radio receiver (may be in a car) can amplify to larger audience. Just like TuneAudio on Nokia C7.
You would - need an FM Transmitter - that is, the appropriate hardware for generating frequencies in the desired range.
It is a good thing portable FM Transmitters can be bought from many electronic retailers. They usually plug into the 2.5mm jack and have a battery for several hours of transmission; there are Android/Phone-specific models as well.
The Nokia C7 already has the appropriate hardware built in. The standard "Android" does not.
Good luck :)