TUAW:

Why would anyone need another maps app when they already have Apple and Google Maps? The main reason is that both Apple and Google map apps need an internet connection. Yes, some map data can be cached, but all of your points of interest need the internet in order to appear.Not so with Maps.Me. Once you load the app, you can download maps for anywhere (including hundreds of points of interest for any corner of the world) while you have an internet connection. When you get to your destination, everything is on your iOS device so you won’t be burning up those precious megabytes.

I can’t find my butt with a map and a flashlight so I always appreciate any app that can help. And for us Canadians who travel and get dinged with ridiculous roaming charges, anything that helps us use our iPhones offline while traveling is welcome.