In the UK, Bing Maps can show OS maps in the browser. It appears that this data extends to their API, and a couple of apps have been built using the API (e.g. http://www.windowsphone.com/en-gb/store/app/leisure-maps/f0a5f695-c8d9-40b2-814f-fbbb9d67a3da, http://www.windowsphone.com/en-gb/store/app/os-maps/452f262a-87c5-44c5-b28a-8718b09533cd), but these are fairly swiftly removed from the Store (I assume licencing issues, but I can't work out if this is instigated by Microsoft or OS?).
However, going to the link above on the mobile browser automatically opens up the Here Maps app (which doesn't have the OS Map option) So:
- is there a way to force the browser to use the website?
- is there any other way to view OS Maps on the phone?
Despite the answer below, when I click on the link in WP8.1, HERE Maps still opens, displaying the default mapping and not the OS Map - is this a difference between 8.1 dev and full, or due to something else to do with the answerer's own phone?