The link to the source code is in the about screen in the app. Hardly buried. I will have it added to the site, I was unaware of this.
I figured it was likely in the app, but for an experiment like this, that appeals to many of the ideals of an open source philosophy, I'm less likely to bother installing it if I'm unaware that it's an open source project.
Obviously the appeal ultimately needs to be greater than just being open source, but that initial bump can't hurt the outcome of the experiment.