Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for tracking development and distribution of software applications. In general, one innovative aspect of the subject matter described in this specification can be embodied in methods that include the actions of: identifying a software application available from a software application distribution system; retrieving at least image data from an image file, which is associated with the software application, from the software application distribution system without retrieving the software application; detecting a watermark in the image data; and storing information associating the detected watermark with the software application distribution system from which the identified software application is available.