You're building a one-way file sharing app.
The other things you're talking about, is your goal to build a point-of-sale or sales management system? What's your goal for differentiating yours against a relatively broad market? A cheap, low-feature alternative to the biggers CRMs and Sales systems could certainly provide a service.
For example, how does your vision compare with the customer management, inventory, product development, etc. from Square: https://squareup.com/ ?
