Apple introduced iOS 9 at its annual developers conference in June, when CEO Tim Cook and other executives highlighted new features -- particularly for the latest iPad -- and a more intelligent Siri assistant.
Today, reviewer Michael deAgonia concluded that iOS 9, although primarily a performance and stability upgrade, was "a clear winner" for newer iOS devices and surprisingly fluid on older iPhones.
"iPad users, especially those with newer iPads, should consider iOS 9 a must-have update, as it unlocks multitasking features that power users have wanted," deAgonia added.
Apple also patched 102 security vulnerabilities with iOS 9.
iOS 9 can be downloaded over the air from iPhones, iPads, and iPod Touches, or through iTunes. From an iPhone, for instance, users must touch the "Settings" icon, then the "General" button on the resulting screen. Tapping "Software Update" will kick off the process.
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