iOS
Play button: power on. Pause or play music, long press for Siri.
+ button: increase volume or multi-task.
– button: decrease volume or multi-task.
Left button (+button on top) : sleep mode.
Right button (+button on top): home page.
Android:
Play button: power on. Pause or play music.
+ button: increase volume or take photos.
– button: decrease volume or take photos.
Left button (+button on top) : sleep mode, multitask.
Right button (+button on top): home page, multitask.
*Please note that the multitask function may not be supported by some of the Android smartphones.