I have used pedometer+ for the past two years, but it hasn't been updating reliably using os 4 (on my SO watch and now on my series 3). So I have been waiting for an update. Maybe this is just me.
I don’t believe there is an app or a way to show “live” steps on your main screen. Duffy app is my favorite and it has a complication that you can use and it takes you to the app on your watch and you can update the step count quite quickly to see your actual step count.
That's true... main face complication updates are limited. Present update rate is roughly 8-30 minutes depending on the developers implementation (and Apple doesn't publish those numbers, as far as I know.)