Snapchat is a multimedia instant messaging app and service. One of the principal features of Snapchat is that pictures and messages are usually only available for a short time before they become inaccessible to their recipients. The app has evolved from originally focusing on person-to-person photo sharing to presently featuring users' "Stories" of 24 hours of chronological content. It has also reportedly incorporated limited use of end-to-end encryption, with plans to broaden its use in the future.