Fantastic tool
I have worked as a statistician for 44 years, and taught statistics for many years. Power and sample size are difficult concepts for non-statisticians and I had the idea of a dynamic graphical exposition about maybe 20 years ago, and it was something I wanted to do. Needless to say I never got around to it, and in any case I did not have programming skills to do it. So I just want to say "congratulations" on a great app. It is exactly what I had envisaged a long time ago. The graphics are excellent and i am sure this will be a great tool for teachers and researchers.