If you're looking for a Pixelmost alternative, Freepik is worth a look. This all-in-one creative suite uses AI to provide a range of tools to speed up your design work. With an AI Image Generator, Mockup Generator and large library of assets, it can help you create professional designs in no time. Pricing isn't clearly detailed, but you can try the toolset for free and upgrade to a premium subscription for more features.
Another top contender is Uizard, an AI-based UI design tool that makes it easier to create and refine product designs. Uizard has features like a text-to-UI generator, drag-and-drop editor and real-time collaboration. It's good for designing mobile and web apps, tablet wireframes and websites, so it's good for a broad range of people, from designers to product managers.
If you need wireframes and prototypes that are easy to use, Visily is worth a look. It's got some AI tools like Text to Diagram Beta and Screenshot to Design, as well as more than 1,500 prebuilt templates and strong collaboration abilities. Visily is free to use for now, with a Pro version planned, so it's a cheap option for teams trying to improve their design workflow.
Last, Mockitt is a full-fledged design, prototyping and collaboration tool with AI-powered tools to generate prototypes and components. It's good for web and mobile app design. Mockitt also has real-time collaboration abilities and a design system for shared assets, so it's good for UX designers, product managers and developers.