Auro, the monster-bumping game from Dinofarm Games, uses strategic positioning combined with magic spells and the titular bumping mechanic to push monsters right off the map. You'll play as the impetuous Prince Auro as he explores dungeons and fights monsters.
He only has nine spells to work with, however, so you're going to have to engage your brain on these procedurally generated maps to win. The game also has a competitive play mode that lets you rank up over time to become the Master Bumper.
You can download Auro: A Monster-Bumping Adventure for $2.99 on the App Store and give those monsters a well deserved bath.