Question: I'm looking for a solution that allows me to validate user flows and interactions before investing in detailed designs or coding.

If you need to validate user flows and interactions before investing in a lot of design or programming work, Mockitt is worth a look. Mockitt is an all-in-one design, prototyping and collaboration tool with built-in tools for prototyping, flowcharting, mind mapping and real-time collaboration. Its AI tools like AI prototype generation and real-time commenting can speed up your design process and help you communicate better with team members. It handles web and mobile apps, and offers a free version with several pricing tiers.

For building optimized forms, quizzes, surveys and onboarding flows, Upflowy is a great option. This drag-and-drop tool lets you build and iterate on customer journeys without any technical expertise. It has features like conditional logic, custom fields and analytics view, and integrates with more than 1000 tools and platforms. Upflowy also offers a free plan and several pricing plans for different business needs, so it's a good option for improving user interactions and conversions.

Finally, Thread offers an AI-based tool for rapidly creating interactive wireframes. Its interface is designed to let designers, developers and product managers create wireframes based on user descriptions with a few clicks. Thread's features include rapid wireframe creation, UX testing and non-designer accessibility, and several pricing tiers to accommodate different needs. It's good for early UX testing and rapid prototyping.