Convert ngg to flif Online: ngg2flif

You can use Tom's Editor to easily convert images from
Nokia Group Graphics .NGG to Free Lossless Image Format .FLIF.
Tom's Editor is a free, online image manipulation and converter program.

Go to Tom's Editor

NGG

Nokia Group Graphics is an image format with extension NGG.

FLIF

Free Lossless Image Format is an image format with extension FLIF.