iOS 7 support offline maps.
You just need to add tiles for specific area.
Tile contains overlay of map so we just need to add that overlay on the map.
For tiles you need to calculate area for which you need offline map and then get that area from OpenStreetMaps.
That's it.
Here is detailed Link tutorial for this.
After getting idea from tutorial you can easily understand the map structure and move ahead.
Cheers.
