Free and open source, it has a great set of tools as well as an intuitive and customisable interface that you can set up in the best way to work with your style of painting.
Krita has been quietly doing its thing since 2004, and it's one of the best-kept secrets in the digital art world. Free and open source, it has a great set of tools as well as an intuitive and customisable interface that you can set up in the best way to work with your style of painting.