It was also Cook's first launch without Apple co-founder Steve Jobs, whose health was deteriorating, and he died the day after the announcement of the On September 10, 2013, the i Phone 4S name was re-stylised as i Phone 4s, using a lower case 's' to reflect the names of the newly announced i Phone 5s and i Phone 5c.
This was unusual for Apple as an upper case 'S' had been used since the introduction of the i Phone 3GS in 2009.
Interaction with the OS includes gestures such as swipe, tap, pinch, and reverse pinch, all of which have specific definitions within the context of the i OS operating system and its multi-touch interface.
Internal accelerometers are used by some applications to respond to shaking the device (one common result is the undo command) or rotating it in three dimensions (one common result is switching from portrait to landscape mode).
Siri can be accessed by holding down the home button for a short amount of time (compared to using the regular function).