MediBang Paint Pro is a free cross-platform paint and drawing tool (a rewrite of FireAlpaca), aimed at manga artists but usable by anyone.
There's a strong core drawing engine with customisable brushes, pressure sensitivity, lots of layer controls and a pile of powerful tools.
The free cloud storage and Windows/ Mac/ iPad/ Android versions mean you really can run the program anywhere.
There's also strong support for collaborating with others, forming groups with other users, working on the same files, and sharing custom tones, brushes and more.
Extras include free downloadable patterns, textures and more, guides for drawing in perspective, and even Voice to Text input.
What's the key new features in 13 (see release history for more info):
- Added the Close Gaps feature to the Bucket and MagicWand tools.
- Added the Export All feature to Comic Projects.
- Added the Tone Curves filter.
- Added Divide to Blended Layers.
Added Mask and Stencil Layers.