back to back histograms or stem-and-leaf plots
I really like the statistics component. But it would be great to be able to compare 2 distributions with either a back-to-back stem-and-leaf or back-to-back histograms. In my mind, box and whiskers are great for comparing 3 or more distributions, as several histograms on a page would be hard to understand. But back-to-back histograms or stem-and-leaf plots are much more insightful ways to compare two distributions. I'd love to see this in a future version.