Instagram is a free iPhone app launched in 2010 that allows users to take photos, add filters and frames, and share the modified photos on social media like Facebook and Twitter. The app is popular among 15-40 year old urban dwellers interested in art, fashion, and photography as it allows quick and easy photo sharing. Brands and celebrities use Instagram to promote products and gain exposure by posting photos to engage followers. Metrics like likes and hashtag usage help measure a photo's popularity and brand awareness. Channing Tatum actively promoted his movie 21 Jump Street using Instagram by posting rehearsal photos that received thousands of likes and hosting online contests.