?Windows Phone 8.1

OS version: 8.10.12359.845, 8.10.12382.878, 8.10.12393.890, or 8.10.12397.895

Cortana. Cortana is here to help you with your day. She can help you call, text, take notes, find stuff on the web, and more. All this while keeping you updated on the things that interest you. (Cortana is currently only available in the US.)

Action center. Simply swipe down from the top of your screen to get to your quick actions and notifications. See what’s new and quickly turn on settings such as Wi-Fi, Bluetooth, and more. You can also change your quick actions to get to the settings you use the most.

Word Flow keyboard with shape writing. With shape writing, you can type by sliding your fingers around the Word Flow keyboard, and then watch the words appear.

Quiet hours. Ahhh… peace and quiet. Take a break from the ringing and buzzing and enjoy the silence. But don’t worry, Cortana can still make sure the people in your inner circle can still get through.

Burst mode. Whether you’re taking pictures of kids, pets, or a sporting event, it can be a challenge to capture a fast-moving subject. Burst mode on your camera helps you get the shot you want.

Data Sense. New settings in Data Sense help you get more out of your cellular data by reducing the amount of data you use when browsing the web.

Battery Saver. Battery Saver lets you keep an eye on your battery and find ways to make your battery last a little longer. See how much battery you have left, what apps are using the most power, and get the most out your battery when it’s running low.

Storage Sense. Storage Sense can help you get more out of the storage space on your phone. Store new apps and downloads on an SD card to save space. You can also go into Storage Sense and see how much space individual apps and games are using. (Not all phones have an SD card slot.)

Wi-Fi Sense. Wi-Fi Sense connects you to more Wi-Fi networks around you, so you don’t have to do it on your own. Get connected and save cellular data.

Office. Office now supports saving Office files to SD cards, which gives you a great new way to share your documents, presentations, and other files. You can also share more things toOneNote now.

Internet Explorer. Get a better browsing experience on your phone with Internet Explorer 11 for Windows Phone. Internet Explorer can now remember passwords, display unlimited tabs, play videos inside a web page, and save you some typing by automatically completing web addresses for sites you frequently visit. There’s more too—such as InPrivate Browsing, reading mode, new browsing gestures, as well as the ability to download and upload files to and from your phone.

More columns on your Start screen. With an extra column of Tiles on your Start screen, you’ll have even more room for the people and things you care about most.

Background photo on your Start screen. Now you can personalize your phone even more by using a background photo on your Start screen. Tiles become transparent, so your background photo shows through.

Volume controls. New sliders now give you separate volume controls for your ringer and for audio played over your phone’s speaker, as well as for headphones and Bluetooth devices.

Calling. Don’t just talk—video chat instead. Switch from a regular voice call to a video call with a tap or two. And you can add the people you call most often to speed dial for quicker calling. (To switch to a video call, you need to have a compatible video calling app installed, such as Skype.)

Calendar. Calendar has a new look. Get a new outlook on your day, week, or month with the new views. Even get a glance at the weather forecast so you know how to dress.

Wallet. Wallet helps you keep track of events, tickets, and more. When you’re in the area, you’ll get reminders for your tickets and alerts for deals around you.

Windows Phone and Windows 8.1 together. Sync your settings, such as your passwords, Internet Explorer favorites and tabs, theme color, and more. When you’re signed in with your Microsoft account, these settings are synced so you can go back and forth between your Windows Phone 8.1 and your Windows 8.1 computer or tablet without missing a step.

Entertaining apps. Xbox Video, Xbox Music, and Podcasts apps deliver more entertainment to you on your phone. Xbox Video lets you browse, buy, and watch videos, movies, and TV shows. Xbox Music lets you find new music, preview it, and listen. With the Podcasts app, you can find new podcasts and subscribe to your favorites so you never miss an episode.

Bing apps. Bing brings you more apps on your phone—including Weather, News, Sports, Health & Fitness, Food & Drink, and more.

Search. From a single place, you can now search your phone for email, text messages, contacts, music, settings, and more. Just use the Bing bar to search, and then swipe over to Phone to see the results.

Update apps automatically. Your apps get updated automatically now, so you always have the latest and greatest versions without needing to download them on your own. Spend more time using your apps and less time updating them.

Dual SIM phones. Some Windows Phones have dual SIMs. With two SIMs, you can keep your work life and personal life separate, or combine the two if you want. It’s up to you. (Dual SIM phones aren’t available in all countries or regions.)

Project my screen. Show your phone on the big screen. Take your USB cable, plug it into your computer, and then you’re ready to go with a tap or two. Or get rid of wires entirely and project your phone to a TV or other device that supports Miracast.

Bluetooth. The Bluetooth Low Energy (LE) profile is now supported, so you can use a wider variety of Bluetooth enabled devices and accessories with your phone.

Backup and restore. Back up more things now—including your Start screen layout, Wi-Fi networks you’ve connected to, and app data (such as high scores and game progress for participating apps). Words you’ve added to your dictionary get backed up now, too.

Enterprise improvements. You might be away from the office, but with VPN you can get connected as if you were there. Use VPN to get a secure connection to your company’s intranet and network over a cellular data or Wi-Fi connection. And when you’re back at work, there’s also support for connecting via enterprise Wi-Fi authentication EAP-TLS and EAP-TTLS.

Accessibility improvements. Use Narrator on your phone to have your screen read aloud. This includes your emails, text messages, settings, and other text.