Bloom is a fast, light-weight, cross-platform procedural graphics editor that lets you tweak any action you have ever performed - organized by layer.
Bloom is the first editor to allow true non-destructive editing. Every filter, effect, brush stroke or vector edit you apply is stored separately, and nothing is baked in. This allows you to come back to anything you've done in the past and adjust it - without redoing all of the subsequent work. Even brush strokes are editable after you've drawn them!