Mr. Matt J. Andrzej Wrotniak
Many programs generate numeric output which needs to be presented graphically. Statmaster is a simple way to do that, reading a text file with data arranged in a space-separated table, and drawing up to 16 pages of histograms and XY plots.
Tiny but smart calculator: just type in any expression, like "2+3/7.1-3sqr 5", and hit Enter; then modify it and evaluate again without re-entering everything. 18-digit precision, 30 functions, 12 memories, fractions, deg/min/sec, more!
Advanced Sci/Eng calculator. Expression evaluation, 18 digits precision, variables, >100 functions, graphs, unit conversion, interpolation, polynomial regression, linear algebra, systems of linear, nonlinear and differential equations, optimization.