What does the spell Flipendo do in Harry Potter?

Answer 1

The Knockback Jinx is a spell which can be used to 'knock back' an opponent, blast jars and creatures or activate magically charmed switches. The incantation of this spell is Flipendo.

This spell only really occurs in the Video Games. It is never mentioned by name in the books or in the movies although it is believed to have been used in the movies as a non-verbal spell. It is still valid as a spell though, as J.K. Rowling has included it in Pottermore.