I use five different applications as part of my ongoing fitness routines. These include Apple Activity, Peloton, RunKeeper, Pedometer++ and Withings.
I use Pedometer++ as an app to track my steps primarily because it provides a nice complication on my Apple Watch. In the app on the iPhone, it also shows how many days in a row you have reached your goal. I have walked more than 10,000 steps a day every day for the last 600 days!