Leonardo is an AI image generator geared for creators, teams and developers. It has a range of features including image generation, AI Canvas for editing, 3D texture generation and fine-tuned models for anime, illustration and photorealism. This is a good tool for inspiration, character design, game assets and concept art, and there are free and paid subscriptions depending on your needs.
If you're looking for an open-source option, Picture it is an AI art editor that uses stable diffusion models to create and edit images. It has tools for fine-tuning image generation, auto-suggesting prompts and generating images with guided drawing input. That makes it a good tool for digital artists and designers who want a simple, high-quality image generation process.