It's become the social media network of choice for post-millennial digital natives, but Snapchat is an app alien to most parents.
Here's our breakdown of what a 'Snapstreak' is and how it works.
A Snapstreak involves two people sending messages back and forth for a consecutive number of days.
The higher the number, the higher your 'streak count' - and for many, the stronger the friendship.
The number can go into the hundreds.
Users are also alerted if the streak is about to end.
The aim of getting and building up a snapstreak is to see how long user's can keep it going; it's one of a few features built into the app that turns it into a type of game.
It's a social media phenomenon that's encouraged plenty of teenagers to boast about their streaks online.