Downtown-based Rock My World has trotted out a new feature on its RockMyRun music app for iPhones — one that plays tunes in synch with a listener’s heartbeat.

The feature, called myBeat Heart, takes its cues regarding tempo from a runner’s smart watch or other wearable heart rate device. The devices communicate via Bluetooth short-range radio signals.

The RockMyRun app, which offers music curated by a disc jockey, comes in free and paid versions. A version that plays music in time with one’s pace is available for iOS and Android devices.

The company said that it is the first to synch music with a person’s heart rate, noting that the feature is appropriate for cycling, resistance training and other sports that don’t have a cadence.

The heart rate feature will be available soon on the Android version of the software, a publicist said.

Rock My World is a tenant in the pro bono EvoNexus incubator. Its CEO is Adam Riggs-Zeigen, a Valhalla High School graduate whose career path included stints at Qualcomm Inc. and as a disc jockey at Indonesian dance clubs.