This app was mentioned in 4 comments, with an average of 1.50 upvotes
Someone made a stripped down app that used the N5 pedometer where you could manually input your stride distance. If I can dig up what it's called I'll add it in an edit.
The Fit app is alright, but I'm a tall guy, and if I'm going up or down a steep grade it registers my steps as riding a bike which fouls any calculations I try to do for distance estimates.
Edit: I think this is it.
this pedometer app https://play.google.com/store/apps/details?id=com.ivon.pedometer
Also technically cpu z if I keep the "sensors" page open, but those are the two I can think of.