I'm pretty new to training. I started using Zwift last winter and did a few of their structured workouts but as soon as the weather started getting nice I decided to cancel my subscription in favor of riding outside and haven't done any structured workouts since.

I commute every day and would like to try using those rides as training workouts rather than just leisurely rides.
I'm wondering if there are any iPhone training apps that allow you to input or choose a workout and it'll give directions as far as heart rate/cadence zones, how hard you should be going etc.

Ideally it'd be great if it was real time and would use heartrate and cadence data (don't have a power meter) as well as voice commands so the phone can be stashed in my pocket.

Does anything like this exist?

Actually sounds like a good idea.

Usually I commit the day's workout to memory and then go off my programmed zones on my bike computer.