Downloading CalcService 3.5.1 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. This free software for Mac OS X is a product of DEVONtechnologies, LLC.
The most popular version among the program users is 3.4. We recommend checking the downloaded files with any free antivirus. The most frequent installer filename for the application is: calcservice.zip. You can run this free program on Mac OS X 10.6.8 or later.
From the developer:
CalcService helps you enter calculations into any Service-aware app, such as TextEdit, Mail, Messages, Safari, Xcode, etc., and calculate the result with a single keystroke. You can append the result to the formula, replace the selected text with the result, or show the result in a panel. You will never need to launch Calculator again if you just need a quick calculation.