Ok, it’s not a downloadable app but it is worth mentioning. Magma Studio drawing session hosted by Wacom at Lightbox Expo 2020 Like Medibang, it’s also a good option for doing things like comics, with nice line art brushes and an easy comic panel maker. But this isn’t too big of a deal for an good app with a solid range of brushes and textures. The effect of that last a few hours at least after which you’ll have to watch again. So you will see banner ads as well as needing to watch one in order to unlock something like different brushes. IBIS Paint is one of the free apps that relies a bit more on advertising.
The Ibis Paint X available for mobile devices IbisPaint X (Available on Android and iOS) Krita also has an extensive guide and tutorial page so if you needs some help navigating the program or figuring out how to do certain things, they’ve got you covered. This could mean some really interest possibilities for painterly animations.
The nice thing here also is that you pretty much get use of all the drawing tools available for drawing your animations as well.
Krita is one of the free options that also has animation features. If you have a Microsoft tablet, this could be an option but the interface might be a little too cluttered. This is the program for computer that I’m more inclined to recommend for painterly work.