Snapchat is a smartphone application that allows you to send ephemeral messages called snaps. The particularity of these snaps is that they will automatically disappear once they have been viewed. However, Snapchat recently updated its app to include a replay option that allows users to replay a snap after the first viewing before permanently deleting.
Open the Snapchat app and go to Settings (represented by a small gear icon in the top-right corner):
Scroll to Additional Services and select Manage:
Check the box that reads Replay to enable the option:
Now return to the main screen. Press and hold on the snap that you would like to replay. A message will appear asking if you would like to replay the snap. Tap on Yes to view the snap again.