If you are a fan of Undertale and you want to call Undertale with Sans, You're in the right Place! is a Prank App to enjoy it with your friends!#Who is Undertale?! Undertale is a role-playing game that uses a top-down perspective. In the game, players control a child and complete objectives in order to progress through the story.Her fans are called Sans.turn on a fake call and show a friend and you will see how he is scared! Disclaimer : You can't make a real call, this is just a prank App!