For quite a while Sketchbook was just about the only artist quality painting app for Android. Corel Painter Mobile, Art Rage, Photoshop Touch and a few others have now joined in.
Sketchbook is compatible with both Android and Apple tablets and phones.
Sketchbook comes in a variety of versions. Current (March 2015) version on my Galaxy Note 4 phablet is the improvement on Sketchbook Pro that calls itself Autodesk Sketchbook. This is the paid-for version. The free variety has few brushes but does show you cut down versions of most of the app's facilities, including layers.
In the pro version of Sketchbook each brush tip can be fine tuned for minimum and maximum width and transparency, spacing, jitter, scatter and other transformations. Smudge brushes, long awaited have now been added to the range.
You have layer transform, text, vector shapes, symmetry mode, Copic colours. All in all a true magician's toolbox!
Corel Painter fans have been delighted to see a mobile version arriving on the scene. Painter Mobile is a painting app for Android only. There is to date no iPad or iPhone variety.
As you would expect, Painter Mobile has a wonderful array of painterly brushes and sketching tools. Charcoal, oils, watercolours that run and blend.
In Painter Mobile layers can be moved and transformed, paintings cropped. Symmetry mode gives intriguing kaleidoscopic images.
Art Rage for Galaxy Note 4 has a few more tools and more scope for fine tuning them than Art Rage for iPhone 6+. You have for instance 11 kinds of oil paint as opposed to 4.
In addition to its painterly choice of brushes, Art Rage has a good selection of blending modes for layers. Unusually, in addition to layers, Art Rage provides a Tracing mode.
Like its famous desktop counterpart, Photoshop Touch is a photo editor. However, like Photoshop itself, Touch can be used for painting.
When I first wrote this page, the Photoshop Touch brush tip was just your actual basic circle, though its width, transparency and fade-off at the edges could be varied. You also had a spray can and a smear brush. Touch has now added another two dozen brush tip varieties. These can be further tuned with a particularly useful visual adjustment tool.
Of course there was and still is a huge variety of other image manipulation tools in Photoshop Touch.
Art Flow, Infinite Painter and Serious Paint can also be considered among the best painting apps for Android. The opportunity to fine-tune these pro-level tools should satisfy the most demanding of digital artists.
Note. I am revising this page in March 2015, but things move so fast in the world of digital devices that static pages go out of date all too soon. For future updates do visit my blog, Seeing Things, where posts are automatically dated.