Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
AndreaMosaic - With AndreaMosaic you can create your own photographic mosaics made with your own pictures.
Invision - Prototyping and collaboration for design teams
Mosaic Creator - Mosaic Creator is professional mosaic tool. You can create your own picture mosaic.
Sketch - Professional digital design for Mac.
WidsMob Montage - Make stunning mosaic photos or montage shape with tiles, which supports both JPEG and PNG files.