Thanks HJ. The pieces are starting to come together for me. However I'm still a bit hazy on how this works from the App Store side. For example, let's say a Shopify merchant is browsing the app store. Sees our app and decides to install/buy at this point. They click Get App, Install App, Accept... during this process, Shopify would need to communicate with us. Since we're a desktop app, that really doesn't work does it? Shopfiy can't talk to the users local install of our app for oath or for our app to respond with pricing, trial period... Seems like for our app to be listed in the app store, they wouldn't be able to install from here. We would need to direct them to our product and install/approve... that way. See what I mean?
Tom