The desire to reduce model-dependency has driven measurement-based modal identification methods, as an alternative to analyzing linearized system models. One such measurement-based method is Dynamic Mode Decomposition (DMD), which has recently appeared in literature. Using this relatively fast DMD algorithm, this paper presents an interactive modal-identification tool for spatio-temporal analysis of measurement data. The tool can automatically scan through measurements, and display the values of oscillation frequency and damping ratio, as well as reconstruct signals. The use of this tool, its options, and visualization capabilities are illustrated using simulated measurements from an interconnected power grid.