pmaCalc combines a scientific calculator, binary arithmetik for programmers, and unit converter in an interesting package. In addition to a fair range of scientific functions, it has an unusual numeric stack, and a binary mode that supports decimal, hexadecimal, octal, and binary arithmetic, with a full complement of logical operators and bit manipulation instructions. Unit Converter for 1000+ Convertions, Euro Calculator ...
Solution Solver
Spend your time accomplishing your primary work and let Solution Solver assist you. Solution Solver can perform dilution equations, conversions, solution problems, radioactive decay equations, and much more!
RecBook
RecBook is a very easy to use Bankbook Reconciliation Calculator designed for those with even the least amount of computer experience.
Napier
PocketPC calculator for scientific, financial, programmer, and time date applications. over 150 functions, 64 constants, 100 memories plus more. Expression based and very easy to use with help on all functions, and auto save of last 10 expressions.
Midget
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!
Convert-O-Gadget
Make conversions from one unit of measurement to another. Includes fluids, weights, distances, areas, circles, temperatures, speed, time, mileage, numerals and fractions. A Custom section lets you "roll your own".