Ride with GPS will work on a cell phone with the cell data disabled, I did this before I got my Garmin. On my old phone I would start a ride then turn off the data and i MASSIVELY exended the battery life of my phone, turning the signal back on to upload the rides when I was done. once I got a new phone, I continued using my old phone as a GPS unit, connecting to wifi to upload rides. You may not be able to see maps if you take it out of an area it is "familiar" with during your ride, but it will overlay the route onto the map when you upload the data.