There's certainly pedometer apps in the Play store, many come up with just a search for "pedometer", unfortunately I haven't used any of them. Some have very high reviews, some have mixed reviews.
What I would do is check out and compare some of the higher-rated pedometer apps, and if you scroll down to the reviews section of an app and click "All Reviews", you will see an "Options" button on the right. Click that, then check the box for "From This Device Model Only" (you will only see this option when viewing the play store app on your phone). This will read your device model, and show only reviews written by people with the same device model. This should help give you an idea of what other Moto G owner's experiences have been with the app (though you very well may get no results, if no Moto G owners have reviewed it yet). You can also check the box "Latest Version Only", if you would like to see only reviews for the most current version of the app. Take this one with a grain of salt, though: sometimes an app will work great, will get a small update which breaks it completely, and then quickly get another update that makes it work fine again.
Hope this helps!