Microsoft has published a guide to developing UICC-based card emulation apps for WP8.1 devices. “In Windows Phone 8.1, it’s faster and easier than ever to create a card-emulation app; you just use the Windows Phone SDK and a regular developer account,” Microsoft says. “You don’t need special privileges to give your app the basic emulation functionality” but “you do have to partner with a mobile operator to launch your app”.