HaiFit is a free health and fitness tracker app developed by Ant Internet Inc. for Android users. The app is designed to help users monitor and record their exercise and sleep data in real-time, and offers personalized reminders based on their goals and habits.

With the exercise tracking feature, users can easily monitor their daily exercise routine and view weekly or monthly exercise trends. The sleep monitoring feature records the time of deep and light sleep, helping users to understand their sleep patterns. The app also offers personalized reminders for users to achieve their daily goals and make healthier lifestyle choices.

HaiFit also offers an incoming call and SMS reminder feature. The app sends incoming call and SMS information to the bracelet, which displays the caller's name or phone number and the sender's name and text message content, respectively.