Instagram is an online service for capturing and sharing photos and video. Acquired by Facebook in 2012, Instagram runs primarily as an app on iOS and Android devices and, as of February 2013, served over 100 million active users. A variety of simple graphical filters are available to enhance users photos with various effects and pictures can be tagged and hashtagged to allow searching by other users. The service provides integration with other social networking services where its trademark square-format pictures can be automatically shared and users can be “followed” in a similar style to Twitter.