CoCalc is a transparent, lightweight calculator for everyday use with some interesting features:

• Always on top
• Fade when inactive
• Customisable fade level for active/inactive state
• Show/hide with global hotkey
• Customisable decimal display amount
• Switchable basic and scientific mode
• Basic mode for everyday calculation
• Basic functions are: add, subtract, multiply, divide, etc.
• Scientific functions are: sin, cos, parenthesis, etc.
• Scientific mode are: deg, grad, rad
• Saveable and printable tape display
• NET/VAT percent keys with user defined value
• Copy/paste support
• Selectable decimal separator
• Adjustable decimal places