Have an option on the screen options to make that screen a Development only screen.

What it does: Limits the screen to the current environment in a way that it can not be published in another environment ie: Development to Test.

Use case: Testing an API, preview a pdf or another file, creating a CRUD or Sync page to run timers and logic by clicking a button, etc. 

This would allow developers to be able to better test their applications and leave does testing tools on the app itself to be used again at a later date, therefore saving time and logic.