Seafoid lets you calculate resistors values from their color bands, and more.
Seafóid
What is it All About?
Seafoid offers a wide variety of electronics-related calculation tasks, for example:
Getting resistor values from their color bands.
Calculating LED dropping resistors
Ohm’s Law
Series/Parallel Connections
Heat sink thermal resistance calculation
Inductances of air-cored coils
NE555 circuit calculation
Vacuum Tube Identification
Download latest version (3.1), Mac OS 10.5 and later
For Tiger users and all people who like it old-school: there is the old version (1.3).
What’s New?
Seafoid 3 is now compatible with Snow Leopard! And it comes with tons of other new features:
Calculating circuits with the legendary NE555 (currently as an astable and monostable multivibrator)
Revamped heat sink calculation. Additionally to the old way (calculating the resulting chip temperature for a heat sink), Seafoid has a new option called “Calculate Appropriate Heat Sink” where you specify the maximum chip temperature and the app will tell you what thermal resistance the heat sink must have.
Seafoid 3.0 combines the clean look of Seafoid 1.x and the function of Seafoid 2.0, plus lots of improvements and new features.
Seafoid is now localizable! The beta release will come with English, German and Greek translations.
Lots of minor improvements like better input information and exception handling.
http://seafoid.org/applications/seafoid/