Requires iOS 5 or higher
Yet another feature Apple should have included in iOS. View and launch apps from a list of selected apps directly from the lock screen when you plug headphones into your iDevice. You will be presented with the launcher screen once headphones are plugged in.
You can choose and rearrange the order in which you want the selected apps to appear. Additionally, HeadphoneLauncher will display the media controls right on the lock screen
Configure options from Setting app
See larger Screenshots below