I've been looking for an Android App to run on a Tablet/Smartphone to use the NS-RAW board with RTKlib. I found on first instance RtkGps (https://github.com/illarionov/RtkGps) but it seems that the programmer has dismissed the project, then I found these guys from Russia (http://geosystems.aero/products/rv#) that have developed a software for real time acquisition on mobile devices with professional equipment. They are almost ready for an update and most probably they will include also some development boards/chipset. If we, as a community, reply massively to their questionnaire http://goo.gl/forms/k4PkHSqnva I'm quite sure they will consider to add at least NavSpark to their supported equipment!
Please try the software and let me know your thoughts