I have worked on hygrid.io and I realize that I am stuck iterating on the product instead of just testing the market. I built it for me, but feel that it has commercial viability for many many others. The product aims to create a platform that saves time for the hundreds of Excel users that log into other systems for their data. Its a pretty good version 1 - https://goo.gl/TypA8q
You answered your own question when you said "I built it for me, but feel that it has commercial viability for many others."
Other than what you said, what problem did you design it to solve? Who are "many others"? What problem do they have?
Why not cruise the Excel forums on the MS support site and see if others have that problem? Enlist some of them to help you find how to market it?