JAYS Headset Control - FREE - Google Play store link
Listening to music via my single-button remote headphones, this app has become a must download. It allows you to have a range of controls for music playback with just the single button.
For example, press the button twice to skip to the next track, three times to go to the previous track etc. Now I can keep the phone in my pocket without having to take it out to change tracks or volume level.
The app was designed originally for the JAYS series of headphones, however most people have had it work on various single button remote headphones; including headphones designed for the iPhone.
Thanks to xxb4xx (http://forums.whirlpool.net.au/user/356817) from the Whirlpool Forums for the recommendation