2. The computer implemented method of claim 1 , wherein the indexing comprises indexing the application page for the native application by a combination of a uniform resource identifier (URI) of the application page and a unique application identifier that identifiers the native application.
1. A computer-implemented method performed by data processing apparatus comprising one or more computers in data communication, the method comprising: for each application page of a native application that generates application pages for display on a user device within the native application, the native application operating independent of a browser application that can operate on the user device: extracting content from the application page, the content including content of a plurality of different content types, the content for each content type being extracted by a corresponding extractor specific to that content type; generating application page data describing content of the application page, the content described by the application page data including text that a user device displays on the application page when the user device displays the application page; and indexing the application page data for the native application in an index that is searchable by a search engine.