Simple Calculator от Mickaël Gatti

Simple Calculator is a lightweight Firefox extension that provides quick access to a calculator directly from your browser toolbar.

Features:
- Basic arithmetic operations: addition, subtraction, multiplication, and division
- Decimal number support for precise calculations
- Clear (AC) button to reset all values
- Delete (DEL) button to remove the last digit
- Clean, modern dark-themed interface
- Fast and responsive
- No permissions required - your privacy is protected
- Works completely offline

Perfect for quick calculations while browsing without leaving your current tab.