I made MP3s in GarageBand that give an audible every 50m (1, 50, 100... 350, 2, etc.) for a given pace. For example, the audible pattern repeats every 70 seconds. I change the BPM in GarageBand for a new pace. I could have done more, but I didn't want to add marks to the tracks I visit. So far, it works very well. I wish there were an app that could do this so I could do more complicated things like a change pace during an interval or changing the current place on the fly which I have been doing on tempo runs (on the track).
Since that works well, I would like similar on the road. I want something like a GPS enabled device to give an audible on a similar granularity. DOES ANYONE KNOW OF ANYTHING THAT CAN DO THIS? I don't like looking down to get pace. Hearing the pace is far better.