Prime Number Spiral 7.32 (by Hermetic Systems)
Software for exploring the Prime Number Spiral (a.k.a. the Ulam Spiral)

Factorizer 9.42 (by Hermetic Systems)
For factoring integers, finding primes and plotting associated histograms

Prime Number Calculator 4.9.4 (by Frequency Software Limited)
Calculate the prime numbers between any two limits. $4.95 for 10 utility suite.

Prime Option 2.2.1 (by Z5Com Pty Ltd)
Prime Option is used to measure what is important and to select the best option.

MITCalc - Torsion Springs 1.15 (by MITCalc)
Geometric and strength designs of spiral cylindrical torsion springs

stairs48.exe 1.0 (by JisawADay.com)
Beautiful 48-pc jigsaw puzzle of a set of spiral stairs looking up to the sky.

Factor Calculator 5.9.6 (by Frequency Software Limited)
Calculate the factors of any number with a single click. $4.95 for 10 utils.

3D SurfTris 1.0 (by 3D Surf Games)
Tetris clone with playing field spread upon 5 different 3D surfaces.

CFB Primes 2.0 (by CFB Software)
Find the prime factors and closest primes of any integer up to one billion (US)

Mathematics Suite 1.0.2 (by Frequency Software Limited)
3 Maths Applications for 1 Price. Free one month trial. Only $4.95 for the suite

Animated Money 1.0 (by Flix Productions)
Teaches coin recognition and math skills using US and Canadian coins.

Animated Arithmetic 1.0 (by Flix Productions)
Teaches addition, subtraction, multiplication and division for 1st - 4th grades.

Animated Math 1.0 (by Flix Productions)
Teaches counting, addition and subtraction with animated rewards.

DB Calc for Windows 3.0 (by Dirk Billand)
Scientific calculator and function plotter for engineers

Count Me! 2.0 (by TeachStyle)
Tutorial. Addition&subtraction,sum,tens,length's units,figures,control tasks.