Game Mechanics Mobile Game walkthrough/tour/intro level/screen

Does anyone know if their is a tool or asset that helps you build a intro/walk-through level to help the user/gamer understand how to play your game.
I have seen them on mobile apps/games before and was wondering if their was a better approach then just build straight from scratch as custom level?
All the tutorials that I have made I have had to make from scratch as a new level; they are not easy to do as you need to be able to tell the player what needs to be done and keep them on the right track.