Windows phone 8.1

Windows phone 8.1 is a new operating system (OS), announced at Microsoft 's Build Conference in San Francisco, California, on  April 2, 2014. It was released in final form to Windows phone developers on April 14, 2014. It will roll out to all current Windows phone 8 users on June 24th 2014, but the date of update depended on country and region. This new OS come with some main features :

Cortana : is a personal virtual assistant that was added in Windows phone 8.1, and it similar to Google Now and Apple 's Siri. It can used for set reminders, recognize natural voice without the user having to input a predefined series of commands, and answer the questions. Cortana also uses special feature called  a " NoteBook", where it will automatically gather information about and interests of the users based on usage and allow users input personal information.

Web : Windows phone 8.1 use Internet Explorer 11 (IE11) as the default web browser which support WebGL, map, swipe left or right to navigate to a previous webpage and back, HTML5.

Storage Sense : lets user move files and apps between their phone's hard drive and a micro SD card, gave users the ability to delete temporary files to free up storage and allows user install apps on micro SD card too.

Multitasking : Windows phone 8.1 adds support for closing apps by swiping down on them in the multitasking view.

Lie Tiles: windows phone 8.1 has ability for users to skin live tiles with a background image.

Notification : More importantly however, the Notification Center also displays four icons at the top of the screen, WiFi, Bluetooth, airplane mode and rotation lock. it also allow the users to customize notification.

Keyboard : Microsoft has added a "Word Flow" keyboard in window Phone 8.1 that, similarly to the Swype keyboard on Android devices, allows users to swipe through letters to type.