What base maps are available for CartoMobile?

CartoMobile supports a few different techniques for rendering base maps.

By default, MapBox's OpenStreetMap is used as the base map in all newly created Maps.

Any WMS or OpenStreetMap-compatible tile server may be used as a source as long as the URL is known (and in the case of WMS, the layer names).

More than one Base Map can be defined for a Map, but only one can be visible at a time (they are always opaque, so it wouldn't do any good to layer them). 

If you have your own imagery (or can acquire georeferenced imagery) in MrSID, JPEG2000, TIFF, PNG, JPEG, or ECW formats, CartoMobile can use these directly (make sure you have a .prj file which declares the coordinate reference system if your format doesn't already encode that data).

For advanced use, CartoMobile also has the ability to store pre-rendered base maps on the device in a proprietary format.   These pre-rendered base maps can be created by Cartographica Desktop and exported by choosing File > Export Image for CartoMobile (hold down the Option key when accessing).