Microsoft announced Windows Phone 8.1 and a Halo-inspired voice-controlled assistant Cortana at Build conference today. Cortana is Microsoft's answer to Apple Siri, Google Now and Samsung's S Voice.
Cortana lets you set appointments, play music and perform searches. It learns from the web searches you perform and the locations you frequent to try and provide contextually sensitive and timely information, similar to Google Now.
Windows Phone 8.1 will also have a new Action Center, which is basically the notification center. Users will be able to customize which apps can send notifications to Action Center. Users will also be able to skin the Start Screen tiles with images instead of just a solid color.
Other new features are Lock screen themes, Skype integration, improved calendar and New apps (Podcasts, Xbox Music and Xbox Video).