I was recommended an App from an iphone user (freegps) but the Android version doesn't look ideal.
I've also seen an iPhone app that can show you where you are on an OS map for £30 inc 1:25000 anywhere in UK, but can't remember is name.
Buying an iPhone not an option as I'm set in my ways!
Gps is (normally) in lat/long. You need to convert to OS grid refs. Do you have the maps?
Viewranger
Like this?
[url= http://www.gridreferencefinder.com/batchConvert/batchConvert.php ]clicky[/url]
Not an app though. The main site is also pretty handy.
There's a Google maps OS grid overlay somewhere around that I use. I'll try and dig out the link, but I reckon a search would find it just as easily.
The OS have a free app that will give you a map grid reference [url= https://www.ordnancesurvey.co.uk/shop/os-locate ]OS Locate[/url]. Not sure if it includes any base mapping. There's also [url= https://itunes.apple.com/gb/app/gb-locate/id299459147?mt=8 ]GB Locate[/url] which is similar and has been around for ages.
Richmars - I've no maps. I've no idea where to start.
I use this one [url= https://play.google.com/store/apps/details?id=com.in_con.coordinateconverter ] for converting SatNav to Lat Long[/url] and this [url= http://www.ngdc.noaa.gov/geomag-web/calculators/mobileDeclination#igrfwmm ] which if you click options gives a Lat Long position.[/url]