Power on X is a Mac OS X native (cocoa) program for the calculation of statistical power. The program can perform calculations of required sample size to achieve a desired power, and calculations of power for previously run studies/experiments. In addition, the paid version can generate power/sample size tables.
Box & Whiskers Drill 1.0 - Middle-School (grades 5 through 9) math program written to provide skills in context. Students use sets of data to construct on-screen box and whisker plots.