GimpPainter 2.6.6 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The most popular version among the application users is 2.6.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The software lies within Design & Photo Tools, more precisely Viewers & Editors. This free Mac application was originally created by The GIMP Team.
From the developer:
GimpPainter can be used for many tasks, including painting, erasing, blurring, airbrushing, inking and special effects. It seems like GimpPainter is no longer maintained and it will never be. Now the program switched to linux OS, the Mac version is the latest developed without any further develop future.
You may want to check out more Mac applications, such as Smith Chart for Mac, Keynote Action Pack or Piranesi, which might be similar to GimpPainter.