Thank you all for your input. Here's a bit more on it: It's not a "millions of users" idea, so scaling for that may not be an issue, but security certainly is

Thank you all for your input. Here's a bit more on it: It's not a "millions of users" idea, so scaling for that may not be an issue, but security certainly is and it will require a team with the experience to make sure it's properly engineered. These are not the kind of users I'm going to impress with a mom&pop, made in my garage, app. That approach is impossible. The marketing effort is likely to be the key to success and the market really needs some in-depth research to design both that and the app. It needs to be studied and brainstormed by a team to do it right, but it is a big market waiting for a solution to be presented so an opportunity exist to design and build and offer one.