The chipset that he used for getting the compass and incline readings (the big feature was that you could do it in any direction - you did not have to keep it flat to get bearing) are obsolete now and not available, also the A3 disto is hard to come by as its discontinued. I believe he is working on modding another Disto with new chipset.
I'ved looked at the Distos and can only find the D8 that has a 360Deg tilt, non of them seem to have bearing? Do you know which one does a bearing as well?
I would imagine that since you need the electronics for the incline reading to make the bearing electronics work well, there is no point in modding a disto with tilt, and you might as well use a cheap model.
If you can get a disto that give bearing, incline then I would imagine it would be relatively simple to get the data into the little app.
Mr Mike www.mineexplorer.org.uk