Convert flif to gbr Online: flif2gbr
You can use Tom's Editor to easily convert images from
Free Lossless Image Format .FLIF to GIMP Brush
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Free Lossless Image Format is an image format with extension FLIF.
GBR are images that can be used as brushes in GIMP image editor.