A few years ago I tested a couple of pedometer apps on my phone. They all drained the battery, because they couldn’t work in the background. That seems to have changed. This one works quite well (it was within a few steps of my wristband tracker), and there isn’t any noticeable impact on battery life.
I think half those steps were at Kroger. The store is huge, and a wristband tracker doesn’t work well when you’re pushing a shopping cart. It’s nice to finally get official credit for those steps!