DiffusionBee is a free, standalone app that uses Stable Diffusion to create AI art on your machine without relying on cloud services. It's got a lot of creative controls, including text-to-image generation, generative fill and training your own model. It runs offline so your data isn't shared, and it's optimized for Apple silicon machines.
If you want a more general-purpose tool, DeepMake offers generative AI-powered content creation abilities like text-to-image generation, face and object masking, and image and video upscaling. It runs on your own machine and integrates with popular VFX and video editing software like Adobe After Effects, so it's good for pros.