單位換算 (Unit Converter Free) is a free unit conversion tool for Android developed by First Bird Technology. It offers a wide range of units of measurement, including weight, length, area, volume/capacity, temperature, power, speed, pressure, and computer memory units. The app also supports multi-country currency conversion, with auto-updating exchange rates. What sets this app apart is its support for the units of measurement commonly used in Asia, such as Hong Kong's tael, China's catty, Taiwan's ping, and Japan's jian.

The app offers real-time conversion and automatically saves the last used unit, making it easier to use next time. It also supports negative numbers and portrait and landscape interfaces. Finally, it supports three languages, including Traditional Chinese, Simplified Chinese, and English. Overall, 單位換算 (Unit Converter Free) is a comprehensive and user-friendly tool for anyone who needs to convert units of measurement or currencies on their Android device.