You can add apps to Apps and Media, either in the target image or afterwards when the system is up and running. You can also configure your Apps and Media system to use a simple, monolithic HMI instead of the default HMI with packaged apps.
If you are an HTML5 or Qt app developer who just wants to get apps into a QNX Apps and Media system, you don't need to modify and rebuild a target image. You can add apps to a system after it is up and running. For instructions, see "Packaging, Installing, and Launching Apps" in the Application and Window Management guide.