Apple focused much more on its iOS operating system during its Worldwide Developers Conference today than it did on the Mac OS X platform. It looks like iOS 9 will have a lot going for it when Apple releases it as a free upgrade this fall. Apple says the upgrade will require much less space than the iOS 8 upgrade, just 1.3GB, down from 4.6GB.

Here are five of the most interesting changes you’ll see when the mobile platform is finally available.

1. Apple has added a low-power mode. When you’re bleeding battery life, the last thing you want to do is hunt around your settings to turn off Wi-Fi, location settings, and so on. Apple is making it easier to save battery life with the addition of a low-power mode that you can turn on with a single switch. The company claims that will add three hours of battery life to your mobile devices. Even without the low-power mode, other improvements to the OS will tack on an additional hour of battery life, Apple said.

2. The Maps app in iOS 9 gets a major upgrade with the addition of Transit, which provides maps and departure times for public transportation. If you’re trying to get somewhere in New York using public transit, directions in Maps will be multi-modal, meaning if you need to take a bus to the subway station, you’ll get both bus and train routes, and your arrival time will include all the time needed to get from one to the other. The maps in Transit include the locations of entrances and exits, along with the time it takes to walk to them. The first group of Transit maps will include New York, Baltimore, Philadelphia, Chicago, London, Beijing, and select other cities. The Notes app will also be enhanced. For example, it will be easy to drag photos into a note, among other things. And a new app called News will provide a way to create a personalized news page that includes a variety of sources—local and national newspapers, magazines, blogs, and specialized publications—and topics.

Check out the 5 things you need to know about Apple OS X El Capitan and learn why Apple Music might be worth $10 a month. And check our buying guide and Ratings for tablets

3. Apple Pay will reach beyond credit cards with the addition of store cards from JCPenney, Kohls, and BJ's Wholesale Club. Rewards cards from stores such as Walgreens will also be added. It will also extend its reach geographically. For the first time, Apple Pay will be accepted outside the U.S. First stop: 250,000 locations in the United Kingdom, including mass transit. Also, Apple said it will deploy a new, inexpensive credit card reader, called the Square, to promote Apple Pay's acceptance among smaller businesses. 

4. Siri becomes much more proactive with iOS 9. If you’re looking at an e-mail about a task you need to complete later, just tell Siri, “Remind me about this when I get home,” and you’ll get a reminder when you pull into the driveway. It’s also context-sensitive, so when you plug in headphones in the morning—once Siri has “learned” that running is part of your morning routine—your music will automatically show up on the lock screen. If you usually listen to e-books in the car, your current book will pop up when you plug your phone into the car’s speakers.

5. Picture-in-picture on the iPad? iOS 9 adds this feature to the iPad Air, iPad Air 2, iPad mini 2, and iPad mini 3. A simple tap will let you reduce the video screen so you can multi-task while watching a movie.

—Donna Tapellini

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