A Color Story - The photo app to colourize your life
Trigraphy - Photo editing app that allows you to make mosaic/abstract looking art.
Live GIF - Convert live photos to GIF
GIF Brewery by Gfycat - Create stunning GIFs from videos & screen recording for free
Photomosh - Turn anything into a vaporwave
WidsMob Montage - Make stunning mosaic photos or montage shape with tiles, which supports both JPEG and PNG files.