I have found what appears to be a good training tool for Android devices - called RUNNAHOO METRONOME. It is basically a Metranome which allows you to do cadence training by running to the various beats of a metronome - there are many other Apps that also do this. BUT this one also uses the phones GPS - which means that while running to any particular BPM, it is tracking your run and , then knowing how far you have run and in what time, can work out your average stride length. This is of particular interest to me - because although I am able to run at a good (highish) cadence 180BPM+, I suspect that my stride length could be better( longer) . Just going out and running 5ks every second day all the time gets a bit boring for me--so this "tool" will give me an interest for some time , I think.