La bàn vệ tinh is a free utility application designed for iPhone users, providing an effective tool for measuring directions in various contexts, such as home orientation, door alignment, kitchen setup, and workspace direction. This app is particularly beneficial for individuals interested in feng shui research and practices.

The application features a precise compass with automatic rotation to measure the user's directional position accurately. Key functionalities include support for the Bát quái compass type, a locking feature for display, and sensor calibration options tailored to different devices. Users are advised to take proper precautions while measuring to ensure accuracy, such as avoiding proximity to electronic devices and removing metallic objects.