The demonstration presents ClaimIt — a tool for extracting views that support a user-provided claim. Such views can assist users in finding evidence of phenomena of interest, criticizing given claims by proposing opposing viewpoints, inspecting the robustness of statements with respect to subpopulations, and so on. To be useful, the view should constitute a "natural" characterization of a significant subpopulation. In a recently published work, we focused on claims that compare groups by an aggregate query, and explored the measurement of naturalness as well as the algorithmic challenge of handling the plenitude of possible views. ClaimIt realizes the framework as an interactive system that enables users to phrase their claims in a convenient user interface, extract supporting views, sort them by different measures of naturalness, and control the weights of individual measures in a global ranking function. In the demonstration of ClaimIt, the audience will be able to suggest and analyze different claims on various datasets. A companion video for this submission is available at https://youtu.be/k2KxyeHzRq8.