A smartphone app for recovering alcoholics that includes a panic button and sounds an alert when they get too close to taverns helped keep some on the wagon.

That's according to University of Wisconsin researchers who developed the tool.

Adults released from in-patient alcoholism treatment centers who got free sober smartphones reported fewer drinking days and more overall abstinence than those who got the usual follow-up support.

A host of smartphone apps are available that feature a variety of options for trying to prevent alcoholics and drug addicts from relapsing.

The study results are based on patients' self-reporting, which is a potential limitation. But addiction experts say the immediacy of smartphone-based apps could make them a useful tool.

The study was published online Wednesday in JAMA Psychiatry.