I've suddenly discovered that double click on headset control button switches to the next song. Is there any other ways of interacting with the phone by using headset controls?
The exact behaviour can vary slightly depending on the app, but in the Music app, a single press means Play/Pause, double press (as you discovered) skips to the next track, and triple press goes back to the previous track.
In Nokia Mix Radio, the button works the same, except triple press isn't supported.
In Podcasts, single press also means Play/Pause, but double and triple press skip ahead and back, respectively, by 30 seconds.
If your headset has more than one button, then the other buttons generally control playback volume.
For more information, see How to: do more with one and three button headsets on Windows Phone (AAWP).
The one button headet
- Skip forward.
In the podcast app you will fast forward for 30 seconds.
Using the free version of MixRadio, you can only skip 6 songs and after that the 2 presses will be deactivated for one hour.
- Skip backwards.
In the podcast app you will fast backwards for 30 seconds.
In radio apps like MixRadio, skipping backwards is not supported so the 3 presses is deactivated.
The three button headet
Same as above for the center button but the two other ones control the volume.