Apps similar to HEISS UI include Comfy, which is open source and free for personal use. Other options are A1111 Stable Diffusion WEB UI, Draw Things and Promptus. In total there are four AI Image Generators like HEISS UI for Mac, Windows, Linux, the web and Android.
ComfyUI is an open-source, node-based workflow engine that empowers creators to design, customize, and run complex generative AI pipelines across images, video, audio, and more.
United States
AUTOMATIC1111's Stable Diffusion web UI provides a powerful, web interface for Stable Diffusion featuring a one-click installer, advanced inpainting, outpainting and upscaling capabilities, built-in color sketching and much more.
Draw Things provides a comprehensive but still easy-to-use, mobile and desktop solution for AI-based art generation. It packs all the power of Stable Diffusion into a sleek, iOS and Mac app that lets you create, upscale and edit AI art, totally offline, free and privacy safe.
China
Promptus is a ComfyUI Windows desktop and cloud platform for generating images, videos, 3D assets, and animations using text and audio prompts, with seamless local and distributed GPU workflows.
United Kingdom
