There are two apps.

The first is PBS Kids, which only has a couple of episodes of Daniel Tiger (that is free) there is also a PBS Kids Channel for $4.99 and that has all the episodes through Season 11. It has been a godsend for us because the channel also has Daniel Tiger "Movies" that are 2 hours long and are essentially 4-5 episodes all linked together.

We have been enjoying the channel and knowing that PBS is getting supported too feels better.

YUP.

Dude, download the PBS Kids video app on your Fire Stick (or Android TV, Roku, Apple TV, cast to your Chromecast from your FREE PBS Kids phone app, whatever). It's 100% free. I have it for free on on Fire Stick, NVidia Shield and have helped people get it on Apple TV and Roku. If you're on a computer, just watch on pbskids.org. Again, and I can't stress this enough, 100% free. My kids watch it literally every day and have never given the app a credit card number.