Shazam is an application that can identify music, movies, advertising and television show , based on a short sample played.
It can now identify songs even when music is being played through headphones.
This feature is only available on android right now.
If you are watching a video on Youtube or Instagram and there is a song playing and you want to know which song it is , simply press the floating Shazam button which they introduced and it will attempt to find the song for you.
Pop-up Shazam seems to be android-only feature right now.
This feature is very useful for Instagram users,where you can now recognize songs which people have posted on their stories, or in their Instagram feed.