Jungle_Tribe

I'm still pretty new to geocaching, and very new to Wherigo!! I use my iphone for both, and have a contract at home for data. However, I don't roam with data due to the massive charges involved. Because of this, I download the geocaches and maps to the phone. My question is this, I'd like to change the default map on the Wherigo app to openstreetmap (or atleast bing) so i can download maps! Google won't let me save the map. Any ideas? Thanks