Hi, I will try be clear.
I will attach you images to collaborate with my explication.
I need that:
1 - User open my app.
2- A first option would is "select yout model phone" (e.g: samsung S9).
3- User select a cover case model (hard cover case).
4- User select the picture, for this point the app is the same like your app, but with a mask (rigid cover case to samsung S9).
5- user edit her picture and send to my server.
6- In the succes operation message, I need offer pay to print now, or pay late in cash, and print when array to my shop.
I think that if we can implement it in HTML5 would fine (but please tell me your opinion). In ionic your SDK work fine and it is simple to implement. Maybe I need implement in each SO.
Basicly I need [login to view URL] but in phone app. Can you sale this? Can you sale somthing to make it?