Hello Laura Partridge,
Who needs an app? Music chosen by the client seems to be the preferred “app” for walking; some clients prefer listening to their “phone book” (audio book). Mix up the bpm for cross training and please be sure to keep the bpm in your client’s training capability.
Natalie aka NAPS 2 B Fit.
So, the client will be walking inside their own home, i.e. they have a treadmill?
Maybe have your client get a Fitbit or heart rate monitor and teach them how to work out at their desired intensity (give them a circuit, a steady state, whatever homework you have set for them), and then let them play their own music.
I wonder if you could make something like this during a session. So the client would get the feel of the intensity and workout that you want them to do, and you audio-record it with her ipod or other technology (phone). Then, she/he could play it back and remember exactly how fast to go, how it felt, etc. Good neural programming, especially if client is a creature of habit.
I have long ago started using my iPhone to voice record modules of programs which I can stitch together as it suits the situation. Those programs can be sent to the client or burnt on a disc. They are very popular with my clients.