AndreaMosaic - With AndreaMosaic you can create your own photographic mosaics made with your own pictures.
Swatches - A fun and accurate color picker for the real world
Mosaic Creator - Mosaic Creator is professional mosaic tool. You can create your own picture mosaic.
ColorSnapper - The missing color picker for Mac.
WidsMob Montage - Make stunning mosaic photos or montage shape with tiles, which supports both JPEG and PNG files.
Sketch Palettes - Sketch plugin to save and load colors into the color picker