If you're looking for alternative digital painting and comic illustration software, there are several options available, including:

Clip Studio Paint, formerly known as Manga Studio, is a digital painting and comic illustration software developed by Celsys, a Japanese company. The software is designed to mimic traditional drawing techniques, offering a range of tools and features that cater to the needs of manga artists, comic book creators, and digital painters. With Clip Studio Paint, users can create stunning artwork, from concept art to finished pieces, using a variety of customizable brushes, tones, and textures.

: Buying a license supports the developers and provides access to official support and updates.