I've been trying to find some piece of software that would be able to "render" arbitrary video within an iPhone screen frame, for purposes of usage in advertisements, etc. That is, I want to create a video with an iPhone in it, showing the iPhone screen running some app.
For example (this would be one static shot; the software I'm trying to find would create a video):
The goal is to be able to get a video example of an app rendered on a backdrop with an iPhone frame without having to actually record footage of the iPhone running the app by using a physical camera (which reduces quality and stability, etc.).
The software can run on Windows, on Linux or as a webapp.