On June 21, 2010, i OS 4.0 (formerly i Phone OS) was released to the public and was made available only to the i Pod Touch and i Phone.
With the announcement of i OS 5.0, on June 6, 2011, a USB connection to i Tunes was no longer needed to activate i OS devices; data synchronizing can happen automatically and wirelessly through Apple's i Cloud service.
The most recent update, i OS 9.3.4, was released on August 4, 2016 Apple's i OS did not have an official name until the release of the i Phone software development kit (i Phone SDK) on March 6, 2008.
Before then, Apple marketing literature simply stated that their i Phone runs a version of OS X, a reference to i OS' parent operating system. It was renamed i OS on June 7, 2010, as, with the introduction of the i Pad, and the existence of the i Pod Touch, the i Phone was no longer the only device to run the mobile operating system.
i OS 4 was the first major release to reflect this change.
In June 2007, Apple released the first version of what became i OS – concurrently with the first i Phone.
The final 1.x series release was 1.1.5, released shortly after version 2.0.July 11, 2008 saw the public release of i Phone OS 2.0, with upgrades through version 2.2.1 made available.June 17, 2009 was the release date for i Phone OS 3.0.It was updated through (and including) version 3.1.3 (release date February 2, 2010).The first generation i Pod Touch and i Phone have i Phone OS 3.1.3 as their newest available version.All i OS versions from 3.2 until 4.0 were made specifically for the i Pad.