Windows Phone 8.1 GDR2 brings support for Microsoft’s Rich Communication Suite App – Messaging+. The app needs to be supported by local carriers and generally comes pre-installed on devices, in this case, on a Lumia 640 XL.
As can be seen in the video by Techrum.vn above, the app allows users to send SMS messages even while in flight mode, by hooking into carriers over IP networks.
It also lets you send files and images and generally acts a lot more like an over the top messaging app than the usual SMS app.
Unfortunately the app works on a carrier by carrier basis, and while the app can be seen in the Windows Phone Store here, most users can not download it.