As you may or may not know, finding free applications (or apps) for the Apple TV is a challenge. Apple is notorious for charging for everything under the sun. They only give you 5 GBs of cloud storage space with your iPhone, for goodness sake!
However, all is not lost. You can watch movies and (older) TV shows for free. There is an app called Tubi that is available for download on newer Apple TVs. This app has some classic movies worth watching and very good children’s programming. I’d personally recommend the Tadeo Jones movies for kids viewing. They’re fun, light-hearted, and not offensive.
Another app worth mentioning is Kanopy, which offers free streaming with your library membership. Overall, the movies are a bit artsy and quirky, but they do have a children’s area.
You can also use Amazon Prime’s video streaming. While this app is not free (I think a Prime membership goes for $8 Cdn / month), it offers pretty good value. In addition, you’ll get 2-day delivery of items you order on Amazon.ca.