PixelFed - PixelFed is a federated image sharing platform, powered by the ActivityPub protocol.
PhotoSpills - Easy to use PC collage software with unlimited design possibilities.
Gab - Gab is an ad-free social network dedicated to free speech.
ShapeX - Shape Collage generator - Photos & Graphics
Friendica - Decentralisation - Privacy - Interoperability
PhotoCollage - PhotoCollage allows you to create photo collage posters from a list of photographs.