Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
Percolator - Percolator: the always fun, supremely unique photo app that is sure to surprise you! FEATURES:
Pixel Art Studio - A purpose-built drawing tool for pixel artists
AndreaMosaic - With AndreaMosaic you can create your own photographic mosaics made with your own pictures.
Piskel - Piskel is a website where designers online create sprites or pixel art.
Mosaic Creator - Mosaic Creator is professional mosaic tool. You can create your own picture mosaic.