My android phone is replacing my graphic pad as my canvas of choice. I'm fascinated with the speed that comes from working with my finger on a very small screen and the ability to integrate images and photographs easily. My primary tool is Sketchbook Mobile by AutoDesk because (1) it has a zillion brush styles with adjustable sizes and transparency, and (2) it lets you work on Photoshop type layers that can be easily resized.
The painting on this card started with a simple face drawing that gradually morphed over several days and dozens of fused drawing layers (including a final dimmed photograph of me in my bathroom mirror) into an abstract that feels eeirily earthy
I completed the work using Photoshop on my desktop. Working small means small images, so I had to resample up to 300 pixels for good print resolution. But, other than that and a brightness/contrast adjustment, this is all phone art.