You have a couple different options for step counting.
The PUML app syncs with your mobile health app or wearable.
If you don't have a wearable, you can use your phone to count your steps by using an app. On iPhone you need to have the Apple Health app and on Android you need to have the Google Fit app.
If you would like to use a wearable, PUML currently connects with Fitbit, Garmin and Apple Watch.
For more detailed information on how to sync your steps, check out these articles.