At the moment this must be considered an advanced topic, but for the adventurous it may be useful to know it is possible to configure the Raspberry Pi to provide it's own Wi-Fi Hotspot.
This is useful to do when there is no Wi-Fi router available (e.g. a rural church), but you still need to link up a tablet or other touchscreen device to Box Of Stops.
For reference, one possibility we are looking at is selling a Micro SD card, with the necessary Raspbian, Box Of Stops and Wi-Fi Hotspot all pre-installed. Please let us know if this would be of interest.