IOS

iOS is the operating system Apple uses for its non-computer devices such as the iPhone, iPod Touch, iPad and Apple TV.

Apps become unresponsive

 * Close the unresponsive app fully by pressing the Home button once to return you to the main screen, then twice more to bring up the list of active apps at the bottom of the screen. Press on the icon of the errant app and hold until the icons begin shaking on-screen. A delete icon (white circle with a minus symbol against a red background) will appear on top of all running app icons. To fully close the application touch the delete symbol.
 * If closing an individual app doesn't work turn the device off and back on again. Hold the power button until "slide to power off" appears on-screen, then power it off.

Device becomes slow, unresponsive

 * Turn the device off and back on again. Hold the power button on the top-right edge until "slide to power off" appears on-screen, then power it off. Cycling the power off and then back on every few days generally keeps iPads, iPods and iPhones running at their best.

Airplay stops working, icon has disappeared

 * Turn the device off and back on again.