I am trying to figure out what happens if they order an app? If the clients wants a free app great but if they want to level it up to paid version, how do I then charge them so it doesn't charge my account?
I think the way it works is...
You are billed of any and all apps that you order on behalf of your client in the App$tore.
The client is unable to order himself.
So, you would need to bill the client separately. Even if you are using the new client billing feature, my understanding is that you would need to set up billing for that as you would any service or line item. It would not billed to the client by Duda just because it is an app from the App$tore.
So, I think you would need to manually cancel any automated billings once the client let you know they want to cancel. In terms of FREE vs paid or higher tiers. I think you just need to know the product(s) going in and let the client know the prices. But again, I believe that the client does NOT have the ability to order or upgrade apps purchased (by you) through the App$tore.
I hope I got that right :-)
Thank you for the fast reply.
I guess the next step for me is to be able to show a potential customer what apps I have. I wonder if I can display the apps on a page via the API like I do the current templates?
If you want to advertise your available apps, I would recommend getting to know them and displaying a menu/explanation of ONLY the ones you are comfortable providing. You would need to set up that menu/page manually, of course.
If you just display them all (like via some connected api), then you will need to support apps that you wouldn't otherwise recommend.
That's the cautious approach, anyhow.
Sorry for the late response but you are in great hands with @Bruce_McCaughan. As he mentioned Duda will only be charging you and you will be responsible for billing your client accordingly (set your own price points). I do know that some of the apps offer white labeled handouts that we can use. They should be in the resources panel of your editor.