Flame Painter is a procedural painting application by Peter Blaškovič available on http://www.escapemotions.com/. It's remarkably versatile, but a lot of experimentation is necessary to figure out what it is capable of, so I'm posting a series of tutorials on how to get specific effects.
This phosphorescent gauzy sea-jelly was uses created a gradient using colors that recall the sea: deep blues, greens and violets. The black background is similar to the images from recent ocean documentaries of benthic depths. The Lighten setting is similar to the Lighten or Screen settings in Photoshop, where the more color you add, the lighter it gets. The Ribbon Brush at these settings creates a snake-like undulating edge that coils and uncoils, criscrossing back and forth on itself, but always slowly rotating around the mouse-location. Move the mouse in curly-cues around a large circle to get the shapes shown here.
These ctenophore-like creatures were created using the Flame brush setting which produces a slowly coiling, steadily contracting wavy edge, which is very similar to gauze or fluid, but is too orderly for a flame or smoke. The brush responds to speed, getting larger the faster you move it, then slowly winding down to a point.
This large sea-jelly was created with the Follow brush, which is given some movement with a small Focus setting, and variation that it usually lacks, using a small Chaos setting. Many passes were required to build up the whole jellyfish.