Image labelling/annotation is the process of identifying or recognizing different units in an image. This can assist us with problems such as categorization, tagging, transcribing, or searching/filtering, based on items or text within photos. This functionality is incredibly useful within social media applications, where users can find photos matching relevant searches. The Postmark project is centered around a mobile application with the capability to identify/label images, based on general objects, places, activities, animal species, products etc.