A new app was launched on the iOS store today which a lot of people are going to find useful.
It's produced by the Ordnance Survey, and called OS MapFinder.
Further tiles can then be downloaded (for either 69p for 1:50 000 or £2.49 for 1:25 000) as an in-app purchase.
Map tiles can be explored, and routes can be added on and plotted. The app will also store routes which have been walked or cycled.
Places can be found using a search by postcode, name or grid reference.
If you want to see more about the app, there's a YouTube video below which shows you a lot more.