Wasnt sure what to title this thread, but that aside im trying to find a wordpress plugin or a webapp or something that will allow me to allow people (customers) submit their own designs to be printed on the back of a phone case? i cant seem to find anything and not sure if there is anything on CodeCanyon that is along them lines, would it be more a custom script or what?
If that is all, why not using a simple contact form plugin, with an upload/attachment button, where people can fill out the form, choose some preferences and upload their design. You get that as e-mail an can work based on that.
If you’re looking for something more advanced like users should be able to register/login, save their drafts, customize them on the fly, live preview,...than I’m afraid that you’re right with your assumption that this will be more of a custom solution, altough I’m pretty sure there is something out in the wild which could come closely to your imaginations.