Are there any iPad apps that I could use to teach my kids coding?

You can try this app: https://www.gethopscotch.com/ It teaches the user how to create games. There are simple-to-follow tools and tutorial to help your child (or you) learn how to create a game. Have not tried it myself, but the reviews sounds promising. :)

Depending on how old your child is, LightBot and ScratchJr are probably good apps to get them started on. As Jacq mentioned, Hopscotch is very popular too, but prob better suited for older kids. https://www.scratchjr.org/ https://lightbot.com/