Intune App SDK questions

Hi All

Hope you are all looking for to the Christmas and New Year break.

Anyway, we have a 3rd party app, an app that is available to the general public via the Google and Apple stores.

What we would like to do is have this app come Application Protection policies if possible.

So, my questions are:

• Would the application's creator have to "Register the store app with Microsoft"
• How long does this process take
• Any barriers, pitfalls or personal experiences here

Info greatly appreciated