DrawIt is a vector editing application with support for bitmap-like image filters. Vector editing as well as the filters are completely non-destructive, which means that a vector layer can still be edited even after a stack of filters has been applied.
Vector editing
DrawIt's vector tool lets you create any shape imaginable, and you can convert text layers to vector as well.
Layers
Every vector, image, or text object is a layer. Layers can be grouped and because a group is also a layer.
Pixel perfect
Built on top of the vector tools is support for 50+ CoreImage filters and other effects like (inner) shadows and strokes.
Stacking effects
Shadow, inner shadow, stroke, gradients, bevel and 50+ CoreImage infinitely stacked and non-destructive.