The only problem with GFlare is that it doesn't seem to be available anymore on the Internet. I couldn't find the author's web site. Flame produces wisps of colored light that can resemble a flame but can also resemble lots of other wispy things. QBist builds random images that have a fairly smooth flow to them and are more full bodied than the tendriled visions that come from Flame. Both of these plug-ins work on the idea that from a central form 8 other versions of the form can be built.
Flame offers more control over the size, shape and color of the generated forms.
QBist is fairly random - you don't really provide any input to the process other than picking the next seed form. Both allow you to save seed forms and reload them later. Flame saves more than just the seed information, so you can edit the parameters of the seed when you reload it later. Flame makes use of a colormap for its coloration. The colormap can be specified using a menu option and can be one of a number of predefined options, a custom gradient or a background image.