I recently discovered this brush in TVPaint and had a lot of fun with it. It allows you to quickly draw quite realistically rendered fire with a brush stroke. It is essentially just a two tone brush revealing your chosen texture. You can also smudge as you draw with the 'shift' setting to create some realistic fire blur.
It's nice to play with but I think it could look out of place or too generic if used on a production. Like using word art or photoshop filters.