Abstract: A computing apparatus includes a processor and a memory storing instructions that, when executed by the processor, configure the apparatus to cause presentation of a graphical user interface (GUI), the GUI depicting primary content, cause presentation of an indicator corresponding to a portion of the primary content, the indicator indicating availability of secondary content, detect user selection of the indicator, responsive to the detection of the user selection of the indicator, cause presentation of an index of secondary content associated with the portion of the primary content, the index of secondary content includes secondary content identifiers that are user selectable, detect user selection of a selected secondary content identifier from the index of content, responsive to the detection of the user selection of the selected secondary content identifier, retrieve selected secondary content associated with the selected secondary content identifier, and cause presentation of the selected secondary conte