Through my readings, I came across this dashboard from Johns Hopkins University's Coronavirus Resource Center (LINK).
Using different data viz elements (line charts, infographic maps and lists), this dashboard is able to track confirmed cases, total deaths, total tested and other values in real-time. Provided this information is accurate, I don't think I've seen a more useful tool for tracking the spread of this novel virus yet.
Sources for the map include the WHO, the CDC, and the European Center for Disease Prevention and Control, just to name a few.