Conducting user testing effectively requires the use of the right tools for creating, sharing, and analyzing prototypes. Popular and useful tools for UX prototyping and testing include Figma, InVision, Marvel, and Balsamiq. Figma allows you to create high-fidelity prototypes with interactive elements, animations, and feedback. It can also be integrated with other tools like Maze, UserTesting, or Lookback for user testing and analysis. InVision is a web-based tool that enables the creation of high-fidelity prototypes with transitions, gestures, and comments. It has its own user testing platform or can be integrated with other tools like UserZoom, UserTesting, or Validately for user testing and analysis. Marvel is a web-based tool that allows you to create low-fidelity or high-fidelity prototypes with simple interactions, animations, and feedback. It has its own user testing platform or can be integrated with other tools like UserTesting, UsabilityHub, or Hotjar for user testing and analysis. Lastly, Balsamiq is a desktop or web-based tool that enables the creation of low-fidelity prototypes with wireframes, sketches, and basic interactions. It has its own user testing platform or can be integrated with other tools like UserTesting, UsabilityHub, or Userfeel for user testing and analysis.