It's on PAYG and I rarely turn data on - I use it almost exclusively as a phone when I'm away from home.

Also as a gps when walking - the gps chip is excellent, much better than my previous phone. So the app I use most is OsmAnd - which stands for Open street map on Andoid, and is my favouite mapping app, and requires no data connection. If that app were unavailable for iOS I probably wouldn't use an iPhone - I prefer Android. (I'm using an Android tablet at this moment.)