JavaScript I wrote:

Calculate the interest on a security deposit.

Play "What's My Word?" with scoring help.

Find the date of Easter in any Gregorian year.

Determine a 13-digit ISBN from a 10-digit ISBN

See how a book title changes with one letter removed

Learn your target heart rate for exercising

Metric Conversion:

Temperature conversion:

Fahrenheit to Celsius

Celsius to Fahrenheit

Weight conversion:

Pounds to kilograms

Kilograms to pounds