I've been impressed with tiled maps https://itunes.apple.com/nz/app/tiled-maps/id472255447?mt=8

Easy to use - and you can create your own maps to use offline with 3rd party app - Map Tiler http://www.maptiler.org

I've been impressed with Tiled Maps.

Easy to use - and you can create your own maps to use offline with 3rd party app - Map Tiler.