Windows single apps run in windows phone,surface

http://blogs.windows.com/windows/b/buildingapps/archive/2014/04/02/extending-platform-commonality-through-universal-windows-apps.aspx

http://blogs.windows.com/windows/b/buildingapps/archive/2014/04/02/windows-store-universal-windows-app-opportunity.aspx


http://www.wpcentral.com/what-is-a-universal-windows-app

http://msdn.microsoft.com/en-us/library/windows/apps/dn609832.aspx


http://msdn.microsoft.com/en-us/library/dn642498.aspx