For those in the UK Back Country Navigator also allows you to download (or cache using proper terminology) the Ordnance Survey maps too. Both 1:25k and 1:50k scales are available, you can select a whole area and download the map files at home on your Internet, then use them or in the field without any data connection.
Generally on the bike i use something different, MMTracker, which allows me to use all my old memory map files is which I have for a lot of the country. It does what i need for planning and running routes and for displaying the overlays we have in the uk that show the legal reasons, so that's my go-to tool. I tend to use BC Nav only if I'm browsing or travelling to an area that I don't have the OS Map files for. Both the above running on a Samsung Galaxy S4, in a waterproof case when in the bike!