How to record a video of a running iOS app for promotional use?

Now, with OSX Yosemite, Quick Time Player has a build-in feature that records your iPhone screen.

• Connect your phone with your Lightning cable to your mac
• Open Quick Time
• File > New Record
• This will open your webcam stream, but you can select the source on the right of the record button: just choose your iPhone.
• Record.

There are two ways you can do this. If you want to run your app using the iOS Simulator, then you can use audio/video screen capture software such as http://camstudio.org/ or http://www.techsmith.com/camtasia.html.

If you need to record a video of the app running on the iOS device, then that would require a slightly more complicated setup. You will need Apple TV http://www.apple.com/appletv/ and a DVR. You would connect the Apple TV to a DVR, then from the DVR you would run an output cable to a TV or monitor. The iPhone and Apple TV needs to be configured for mirroring. Afterwards, you should be able to project and see your iOS app running on the screen (over Wi-Fi) while you are recording the running iOS app on the DVR.

I suggest this app http://soundstageapp.com/

It captures the app operation in video and provides tools for entire production of the promo video.