Stable Diffusion Sketch is an Android app that allows users to create colorful sketches and enhance them using various modes of Stable Diffusion. Users can create new paintings using blank canvas, camera capture, Stable Diffusion txt2img, and images shared from other apps. The app also offers preset modes, custom modes, painting tools, undo/redo functionality, and options to adjust prompt prefix, postfix, and negative prompt values. There are three canvas aspect ratios available: landscape, portrait, and square. Users can also enlarge the image using the upscaler feature or delete them from the main screen. Grouping related sketches is also possible, and the app supports multiple ControlNet.