Apps similar to Numbat include Wolfram Alpha, which has a free version. Other options are SpeedCrunch, Qalculate!, PTC Mathcad and Calculator You. There's no shortage of Calculators like Numbat, with more than 50 alternatives for Windows, Mac, Linux, Android and iPhone.
A powerful, scriptable, modular calculator aimed at scientific, engineering or computing work. All features can be added, removed, and customised, and new features can be written in python.
United States
Soos is a calculator you type into like a notepad. Each line is worked out as you type and its answer shows up beside it. You can label lines, name values and reuse them further down, and total a block with "sum".
Vietnam
RJ Calculator is a scientific calculator with most basic functions like trigonometric functions, logarithms and base conversion. Also, statistic calculations like standard deviation and regression.
