The most ambitious is Topaz Labs, a collection of AI-powered photo and video editing software for professionals. Its Gigapixel 7 tool can upscale images by a factor of 600 using large AI models, but it runs in a locally executing application that doesn't send data to servers. That's good for pros who need heavy-duty and private image processing.
Another good option is SuperImage, an AI-based image upscaling tool that uses the MNN deep learning framework and Real-ESRGAN algorithm. It runs on your device, using your GPU to keep data private, and is available for Android and Windows (x64) with macOS and Linux support on the way.