Prototype tools are essential for designers and developers to create interactive mockups and prototypes of web and mobile applications before the actual development phase. These tools allow users to visualize the user interface, test functionality, and gather feedback from stakeholders, ultimately streamlining the design and development process. Here are some popular prototype tools used in the industry:

1. Adobe XD: Adobe XD is a powerful design and prototyping tool that enables users to create interactive prototypes for web and mobile apps. It offers features like artboard-based design, real-time collaboration, and seamless integration with other Adobe Creative Cloud apps.
2. Sketch: Sketch is a vector-based design tool primarily used for creating UI/UX designs, but it also offers prototyping capabilities through plugins like Sketch Prototyping or InVision Craft. It’s known for its intuitive interface, extensive plugin ecosystem, and robust symbol management.
3. Figma: Figma is a cloud-based design and prototyping tool that allows real-time collaboration and prototyping within the same platform. It offers features like multiplayer editing, responsive design tools, and interactive prototyping, making it ideal for distributed teams.
4. InVision: InVision is a popular prototyping tool that allows users to create interactive mockups, clickable prototypes, and design presentations. It offers features like screen transitions, hotspot linking, and user testing capabilities, facilitating seamless collaboration and feedback collection.
5. Axure RP: Axure RP is a comprehensive prototyping tool that enables users to create complex interactions and dynamic prototypes for web and mobile applications. It offers features like conditional logic, data-driven interactions, and robust documentation capabilities, catering to advanced prototyping needs.
6. Proto.io: Proto.io is a web-based prototyping tool designed for creating high-fidelity interactive prototypes for web and mobile apps. It offers a drag-and-drop interface, customizable animations, and device-specific previews, making it easy to design and test prototypes across various devices and screen sizes.
7. Marvel: Marvel is a simple yet powerful prototyping tool that allows users to create interactive prototypes and wireframes with ease. It offers features like screen linking, user flows, and real-time collaboration, making it suitable for both designers and non-designers alike.
8. Justinmind: Justinmind is a prototyping tool that offers advanced interaction capabilities and dynamic content simulation for web and mobile applications. It features a drag-and-drop interface, reusable components, and integration with other design tools like Sketch and Photoshop.
9. Origami Studio: Origami Studio, developed by Facebook, is a prototyping tool specifically designed for creating interactive prototypes and animations for mobile apps. It offers features like gesture recognition, physics simulations, and code export capabilities, allowing designers to create rich and immersive prototypes.
10. Balsamiq: Balsamiq is a wireframing tool that allows users to create low-fidelity mockups and prototypes quickly. It features a sketch-style interface, pre-built UI components, and collaboration capabilities, making it ideal for rapid prototyping and iterative design.

These prototype tools cater to different design workflows, preferences, and project requirements, offering a range of features and capabilities to meet the diverse needs of designers and developers alike. Whether you’re creating simple wireframes or complex interactive prototypes, choosing the right tool can significantly enhance your design process and collaboration efforts.