A recently leaked Windows Phone 8.1 Software Development Kit (SDK) has provided an early look at some features Microsoft is planning for its next mobile update. However, the software maker is also planning many more additions in time for April that aren’t immediately visible in the developer kit. LiveSino reports that the SDK includes references to a change your phone’s background option to set a background image beneath the Live Tiles on the Start Screen. Windows 8.1 introduced such an option on tablets and desktop PCs, and Windows Phone 8.1 will provide a similar feature to match the Live Tile accent color. Sources familiar with Microsoft’s Windows Phone plans have revealed to The Verge that the company is also currently experimenting with a three-column layout for the Start Screen across all devices.