Selecting content-enhancement applications

Techniques for enhancing content being rendered on an electronic device are described herein. In some instances, the techniques include monitoring interactions between a user and a content item that the user consumes on an electronic device. The content items may include electronic books, songs, videos, documents, or the like. In response to detecting an interaction between the user and the content item, the techniques may publish an event indicative of the interaction to an application platform that hosts one or more applications. The applications may be designed to enhance the content that the user consumes in one or more specified ways.