What's new in Android 4.4, KitKat?

Once you've upgraded your phone, you’ll see the following improvements to the Android operating system and other apps on your phone:

• User interface. The interface is now brighter, with larger icons and an immersive mode where apps can fill the entire screen, hiding the status bar and navigation buttons. When in immersive mode, swipe from the top or bottom edge of the screen to see your status bar and navigation buttons.
• Easier to make calls with the Phone app. The updated Phone app automatically prioritizes your contacts based on the people you talk to the most. You can also search for nearby places and businesses, your contacts, or people in your Google contacts.
• Printing. Print photos, docs, and web pages to Google Cloud Print, HP ePrint printers, or other printers that have apps in Play Store.
• Improved lock screen. Control music and videos from lock screen. Access the camera by swiping left from the right edge of the lock screen.
• Camera. Enhanced the "touch to focus" option with a new circular, on screen control that can be dragged by your finger around the viewfinder to adjust a photo's focus and exposure.
• NFC Host Card Emulation. Enhanced support for NFC Host Card Emulation (HCE), to improve experiences such as contactless payments, loyalty plans, transit passes, card access and more.
• Gallery app. You can now save your custom filters, use more effects (highlights, edges) for editing your photos, and draw freehand on them.
• Emoji. Now you can insert emoji, the colorful Japanese characters, using the Google Keyboard.

Other improvements include:

• Now you can say "OK Google Now, find my phone" to ring and locate your phone.
• New version of Google Hangouts that supports integrated SMS/MMS messaging. To set Hangouts as the default SMS app go to Settings > More (under WIRELESS & NETWORKS) > Default SMS app.
• It's easier to insert pictures and videos in emails and text messages.
• Ability to display captions in videos that support captions. Go to Settings > Accessibility > Captions.
• You can now control what location information your phone shares with location-based services right from the quick settings.
• Support for Square Register credit card reader.