SpeedCrunch - SpeedCrunch. SpeedCrunch is a high-precision scientific calculator featuring a fast, keyboard-driven user interface. It is free and open-source software, licensed under the GPL. Download Documentation Donate .

Calcbot for Apple Watch - Calculate, convert, and split tips from your wrist

Sellertour PayPal fee Calculator - PayPal Fee Calculator is a simple and effective free tool that allows you to calculate your PayPal...

SpeQ Mathematics - SpeQ is a small, extensive mathematics program with a simple, intuitive interface.

WolframAlpha - WolframAlpha brings expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels.

Qalculate! - Qalculate! is a multiplatform multi-purpose desktop calculator.