 Background: Interactive and mobile technology to manage alcohol use problem potentially provide continuing care by offering emotional and instrumental support anywhere and in time, but the effectiveness for maintaining abstinence has not been examined. the investigators will evaluate in this study whether the smartphone-based support system would improve outcomes for people in recovery for alcohol dependence. To enable continuous self-monitoring and self-management, the phone support system prompts subjects to take Breath Alcohol Concentration BrAC tests using a phone application and a Bluetooth sensor unit. The system also offers instantaneous feedback, self-management strategies, and anonymous mutual social support from other subjects. 