Snapchat is an app where users regularly use emojis to express their stories and feelings in a more visual way. Now, each user gets up to 8 best friends on it. These are the people they interact with the most and send the most number of snaps to. So as an indicator of their friendship, each user is assigned with snapchat sunglasses emoji or friends emoji to signify the achievements like when they both have exchanged snaps over a long period of time or consecutive number of days, also known as a Snapchat streak.