The SwiftUI App protocol looks simpler but is decisive for your applications' structure and organization.

This sketch note shares a general look at the parts involved while implementing your app's entry point.

Things to take in mind:

1. The App protocol represents structure and behavior.

2. The body is the content and can define scenes.

3. Scene acts as the root view of the view hierarchy and can be more than one.

4. The @main initialize and call the main() method which runs your app.

5. The init() runs by default.

6. You can have multiple scenes whose lifecycles will be managed by the system.

I hope this sketch note is helpful to you.