In Short

Snapchat is a social media app that allows users to send photos, videos or text to other users on their contact list. The "snaps" have a controlled time limit of which to view before they expire. For example, a user may send one photo to a contact with a time limit of 30 seconds. The recipient will have 30 seconds to view the photo, after which it becomes unavailable. 

While an official Snapchat app for BlackBerry is not available, BB10 users have had success sideloading the Android version of the app. There is also a native third-party client in the works for BlackBerry 10 users.