Apple iOS 9 Release: Why You'll Want to Upgrade

— -- Apple's iOS 9 is set to go live later today with a slew of new features designed to provide users with a more proactive experience.

The upgraded mobile operating system will be available for the iPhone 4S and later, most iPads, including the forthcoming iPad Pro and 5th and 6th generation iPod Touch devices. The updates are expected to go live around 1 p.m. ET.

Users can upgrade via a push alert they may receive or by going to settings, general and then choosing "software update."

Here are a look at some of the standout features -- starting with a smarter Siri -- that users can look forward to having at their fingertips:

Smarter Siri

Siri, Apple's virtual personal assistant, is undoubtedly the star of the operating system update with her ability to pick up context throughout your day.

In iOS 9, Siri will be able to pull up results for requests such as "Show me photos from Utah last August" and "Remind me to grab my coffee off the roof of my car when I get in."

Siri will also know to pull up music when headphones are plugged in or start an audio book a user has been listening to when they're in their car, among a slew of other context-based features.

HealthKit

HealthKit, which launched with iOS 8, will include new tracking capabilities for reproductive health, hydration and sun exposure.

Added Search Intelligence

When a user performs a search, iOS 9 can "search deep" within your apps, according to Apple. For example, even if you can't remember which app you saw an apple pie recipe in, if you type "apple pie" in the search field, the recipe will pop up, making for a for a seamless user experience.

The added intelligence is done only on the device level and stays within the user's control. Any requests that require a search, such as traffic conditions, won't be tied to a user's Apple ID.

Multi-tasking

Apple is bringing multi-tasking to the iPad with iOS 9, including the ability to work in two screens at once or even watch a video with "picture in picture" mode.

Recognizing that some people use iPads as computers, quick-type iOS 9 shortcuts will also be added.

Better Battery Life

Low power mode in iOS 9 lets users extend the battery life of their device by an extra hour before charging.

Other energy savings come from little changes, including sensors that let your iPhone know if its face down on a table, allowing it to save power even if the phone receives a notification.