App for Simple, Magical Sign Offs

Hey all

I've been looking at building something that would allow for super easy project sign offs, for eg. between service providers and clients, for deliveries, for critical code deployments within a company. These could have version control (for multiple version sign approvals) and cryptographic signing for technical and legal security.

Is this something that you think would actually be useful? Could it be a stand alone app, or better integrated into things like MS Office or Git?

Would love to hear some thoughts on whether this seems like a good idea or not!