MyPaint is a fast, distraction-free, and easy painting tool for digital artists. It supports graphics tablets made by Wacom, and many similar devices.
Free • Open Source
What is MyPaint?
MyPaint is a fast painting program with an emphasis on full-screen use. It lets you focus on the art instead of the program. You work on your canvas with minimum distractions, bringing up the interface only when you need it. MyPaint supports pressure or tilt sensitive graphic tablets and comes with an easy-to-use brush collection. There is a complex interface for creating own brushes, focusing on brush dynamics (changes with speed, pressure, randomly).
If you uses a Mac getting this app working will be complicated: You need to install MacPorts, which requires Xcode + Xcode Command Line Tools (which is over 5 GB!) Wasting 5-6GB of disk space for a simple app? Not worth it.