iOS Pick: ArtRage
Leo Laporte's app cap on iOS Today 281 is ArtRage from Ambient Design Ltd. This is a natural material painting program, and it's especially great on the iPad Pro with Apple Pencil. This app is very accurate in reproducing the effect of painting on different materials and with various utensils. It simulates the properties of paint such as wetness and thickness so you can smear paint and blend colors. It has access to a full range of Photoshop Blend Modes and a variety of texture effects. It also supports unlimited layers that can be rearranged or hidden as needed, and you can export individual layers.
ArtRage works with Adobe Creative Cloud, Dropbox, and DeviantArt Sta.sh accounts.