I started thinking about Byzantine chant when (in ca. 1995) my friend Martha A. Mills, was talking to me about learning to sing it. Singing these chants is a dying art, and it doesn't help much that it's a hard kind of singing to learn, and must be learned from a master.
Why is learning to sing these chants so hard? A large part is that there are several different scales, and they are not like the scales in western music (to start with: instead of 12 possible divisions per octave, there are 72). Another hurdle is the notation, which looks like this:
This notation is based on relative rather than absolute pitch: the starting pitch is given; from there, the notation indicates how far up or down to go to the next note. Added to this are lots of different kinds of ornaments. (Oh, and you need to be able to read Greek at least enough to pronounce the words.)
If there were a tool which would help you practice the chants more easily on your own, it would remove at least some of the hurdles that stop singers from learning the chants. Also, a tool designed with the assistance of masters of chant singing could help preserve (and even codify) the practice and teaching methods.
The tool for helping people practice Byzantine chants would be something like a music sequencer, but it would have these differences and special features:
I didn't make much progress on this project (I spent most of my time studying the scales and the notation; I didn't get far enough that I felt I could do anything more than very preliminary design of the software), but I think it's a worthwhile one.