Microsoft originally allowed Android and iOS users to control desktop PCs from their smartphones last year, but Windows Phone support was missing. Starting today, Microsoft is rolling out a preview version of its Remote Desktop app to let Windows Phone users control their PCs on the go. The app is available for free from the Windows Phone Store, but the only catch is you’ll need to be running Windows Phone 8.1 to access and install it. Windows Phone 8.1 is due to start rolling out to existing devices in the coming weeks and months, but you can gain access to the update early using a developer preview option.