Upscayl is a free and open source AI tool used for image upscaling. Key features and advantages include:

• Compatibility: Upscayl is compatible with various operating systems including MacOS, Linux, and Windows.
• Easy-to-use interface: Upscayl provides an easy-to-use interface that allows users to upload images, choose the desired upscale factor (2x, 4x, or 8x), and then upscale the image.
• Advanced AI algorithms: The tool utilizes deep learning algorithms to create new pixels based on existing ones and then enhances them to produce higher resolution images.
• Open-source: Upscayl is built using open-source libraries, which makes it stand out among commercial tools used for the same function.
• Supported by donations: The tool is also supported by donations from users on their BuyMeACoffee page.

Use cases for Upscayl involve image upscaling for various purposes, such as:

• Enhancing the quality of images for personal use
• Improving image quality for professional purposes, such as graphic design or photography

In summary, Upscayl is a user-friendly and free-to-use AI image upscaler that produces high-quality results by using advanced AI algorithms. It is a great tool for anyone who wants to upscale their images without losing important details, and who wants to do so using open-source software.