Interactive digital content for printed materials is provided using applications executing in a smart pen computing system. The applications and the printed materials may be developed by separate entities but appear well integrated from the perspective of a user of the smart pen computing system. Printed content produced by a first entity is obtained. The printed content is associated with a dot pattern. An application associated with the printed content and linked to the dot pattern is produced by a separate second entity. The application includes computer program instructions for, responsive to a selection within the dot pattern, invoking a function related to the printed content. The selection within the dot pattern may be made using a smart pen device, and the function may include presenting output to a user through an output device (e.g., a display or speaker) of the smart pen device.