NEW YORK, May 1 — Several smartphone apps can add a helpful boost of motivation, or just provide some fun information, to a run or walk. — New York TimesThe ROCKMYRUN app is full of mixes of music that are timed to match different beats per minute. — New York Times pic
The ROCKMYRUN app is full of mixes of music that are timed to match different beats per minute. — New York Times pic