Things to consider…
>>> Learning curve
All these apps allow you to create complex artwork if you have the skills, but it’s also vital they’re accessible to beginners so they can develop skills.
>>> Brushes
At the heart of every art app is its selection of brushes. In some apps these go way beyond simple textures, with incredible oil, blending and 3D effects.
>>> Traditional or modern
Some apps are geared towards creating more traditional paintings or drawings, while others lean towards modern typography, graphics, and design.
>>> Output and sync
More output options means more flexibility in terms of getting your work off your iPad. In some cases, cloud sync lets you work on projects in other apps.