Methods, systems, apparatus, and computer storage mediums for receiving an initial index, the initial index associating each application of one or more applications with one or more applications of interest; for each application, receiving metadata associated with the application and receiving metadata associated with each of the one or more applications of interest; processing the metadata to selectively remove at least one of the one or more applications of interest from the initial index to provide a final index, the final index associating each application of the one or more applications with a remaining one or more applications of interest; storing the final index in memory; receiving a user selection of a particular application of the one or more applications; retrieving the one or more applications of interest based on the particular application using the final index; and providing the one or more applications of interest for display.