has an interface similar to Microsoft Powertoy Calculator and it offers great features like history, conversions, many functions. And it's a great open source replacement to the calculator included in Windows accessories. It has been translated into 15 languages.
The extension is fully funcional only has some minor visual glitches. Thee are three empty buttons, there sohuld be icons but... you know. The first button (from left) clears the last entry in the input field, the 2nd clears the history and the 3rd hides/shows the keyboard (the last one stands for sqrt)
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