1. A method comprising: receiving, by a mobile device, user input that defines a portion of a digital image; selecting, by the mobile device, the portion of the digital image defined by the user input as a selected portion of the digital image; providing, by the mobile device for presentation to a user after the selecting of the portion of the digital image as the selected portion of the digital image, a list of selectable options associated with respective data instances; receiving, by the mobile device, a user selection of a particular selectable option included in the list of selectable options, the particular selectable option associated with a particular data instance included in the data instances; and applying, by the mobile device in response to the receiving of the user selection of the particular selectable option, a tag to the selected portion of the digital image, the applied tag providing an association between the selected portion of the digital image and the particular data instance associated with the particular selectable option.