Unfortunately, the B+ was released halfway through the development of PiScreen. Therefore all development was based on these models.
You could use a ribbon cable like this;
http://www.adafruit.com/blog/2014/07/22/new-products-downgrade-gpio-ribbon-cable-for-raspberry-pi-model-b-40-pins-to-26-pins-gpio-ribbon-cable-for-raspberry-pi-model-b-40-pins/
Mark --OzzMaker.com --
