I have an app like that too. It's awesome, like a scanner in your pocket.
But, I agree. Most companies still rely on faxing, which is based on pre-Internet technology. I think it has to do with people's continued obsession with having a hard copy.
But not every business still relies on fax. I just bought a house and all of my offers were done via electronic signatures. So, the tide is slowly turning. That said, when I think of the NFL possibly migrating to online signatures, I get a picture of Buddy Nix in my head and I quickly dismiss the possibity.