The built-in speakers on most Android smartphones are OK in a pinch, but a nice pair of earphones always sounds better. Now, you can automatically launch TuneIn Radio, Slacker, Winamp, or any other audio app when you plug your earphones into your Android phone. Here's how:
First, search the Android market for Plug In Launcher and install it.
When you start Plug In Launcher, it'll go straight to the Headset tab and display four options. To select your favorite music app to launch, touch the area where it says, "Click Here to Assign," marked here with a red arrow.
You'll see a list of installed apps on your phone to choose from. To launch Winamp automatically, just select the app from the list.
After selecting your app, the application icon will now be displayed in Plug In Launcher. That's it--you're done! If you want, you can also set a default media volume, have Plug In Launcher automatically play the app, or display a dialog when it detects a headset connection.
Enjoy your tunes!