The main tool I use to create my artwork is Celsys’ excellent Clip Studio Paint and today (well, technically yesterday) version 1.5.0 was released. This update is a major one: now CSP allows you to create animations! Check out the sample movie below, which is from Celsys’ website.
One minor downside to this update is that files saved with the new version of CSP will not be readable by earlier versions. However, the previous version I was using was not overwritten when I installed the new version, which means I can still use the previous version.