I use an older iPhone 4s a friend gave me after he upgraded. No data plan yet either. I use the apps a lot.

I like Cyclemeter's freebie version (I think the Android equivalent is Cyclometer?) to record my basic ride data: distance, speed (also broken down per mile segment), route. Even without a data plan the GPS works and I can review the route map later after I have wifi connection. I may upgrade to the paid version, which records more data, and eliminates the ads.

And I downloaded "OSM and Maps" to the phone so I have realtime map access as I need it. It's a little slow but I only consult it when I'm hopelessly lost.

Tried Strava, Map My Ride, Ride With GPS, didn't really care for 'em for my casual purposes. I'm not really interested in what other riders are doing, competition, etc.