This has great potential!
Downloaded this because I wanted to make a mosaic table top and this looked like I might be able to use the limited colour palette in Lego which would give me a simple guide. Unfortunately it does not have scalability. If I could scale the size of the tiles and the size of the workspace to render a realistic image this would be a killer app for artists wanting to create Roman/Byzantine/Islamic style mosaics. So many more uses in paper, graphics, tile etc. no need to add more colours because greyscale images are easily transferred to colour, just need a very minimal palette to play with.