Awesomap

See more of the world at once!
Awesomap gives you the iOS maps you already use and love, but makes everything quite a bit smaller and sharper, so your screen can show significantly more of it – four times more, to be precise. More street names and points of interest. Sharper satellite imagery. Oh, the sheer amount of detail! Exactly what the Retina display was meant for.
In case the double precision makes things a bit too small for your liking, you can also choose another, more comfortable scale. (Setting the scale slider to the minimum gives you the exact same scale as the normal iOS Maps uses.)
Just remember – Awesomap also eats four times more map data, so it's best suited for use over a fast Wi-Fi.