Format WBMP is older graphical format used mainly in older mobile phones. Its whole name is Wireless Application Protocol Bitmap Format and it is often shortened to WB – Wireless Bitmap. It was created by group called WAP Forum. Its main disadvantage is impossibility to use more than two colors that are black and white. It´s using 1bit bit depth and in practice it means that the pixel is on or off. Because it uses drawing of certain pixels we can move it to the format family using raster graphics.
Originally it was created for mobile phones. Format WBMP was part of WAP protocol, which was standard for connecting to the internet on mobile phones. It was used in the first version of WAP protocol. Then in second version they used casual formats like GIF, PNG or JPG.
Today this format isn´t used anymore, but for few fans there are several programs that are able opening them. We can mention IrfanView. Then there is XnView. It is completely for free and it can both view and edit this file format.