欢律 is a free iPhone app developed by Guangdong Heytap Technology Corp. Ltd., falling under the Utilities & Tools category. The app focuses on providing convenient features for managing earphones. Users can easily check the battery levels of their earphones and charging cases. Additionally, it allows customization of earphone controls, such as modifying actions for "double-tap" and "triple-tap" functions. The app also supports over-the-air firmware updates for earphones and enables access to various unique features based on different earphone models.

iOS欢律 is compatible with a range of earphone models from OPPO and OnePlus, including OPPO Enco X2, OPPO Enco Free3, OPPO Enco Free2, OPPO Enco Free2i, OPPO Enco Air3, OPPO Enco Air2 Pro, OPPO Enco Air, OPPO Enco R Pro, OPPO Enco Play, OnePlus Buds Pro 2, OnePlus Buds Pro, OnePlus Buds Z2, and OnePlus Buds 3.