API for Mobile App File Upload

I’m working on a user registration app that involves both the web and mobile. I know how to write the server side code(PHP) to accept and process file uploads, if the file is coming directly from a web page, but in the case of the file being sent via a mobile app, I wonder, how the code is going to change?

I guess it depends on how the app works, but I don’t think I would expect the server side code to be any different.

Creating separate APIs for servicing different devices kind of goes against one of the primary advantages of APIs to begin. That is creating a single API that can be used across many different platforms. The client side code will obviously change but the API should not which processes and handles the data upload. One API all devices unless a device requires a specific workflow modification but even than the variant API should be developed with reuse in mind and tightly coupled to a single client device or environment.