1st Calculator Cost: $15 Get the full version     Trial version     Developer's Website Contacting third-party download site please wait. If your download does not start, click here, or get the full version Descriptions 1st Calculator: 1st Calculator is a handy and useful expression calculator and unit converter with skins. Main features: fully customizable interface with skins; keyboard shortcuts; all arithmetic operations, more than 20 functions; editable lists of constants and unit conversions; recalling previously used expressions; five result formats with changeable precision; automatic clipboard copy/paste; minimizes to the system tray.