Obtain Grid Reference

Have look at 'MyWaypoints', maybe it's what you looking for.

I don't use it because I can't save the grid, only as email with the coordinates of waypoints.
I'll prefer saving it as track/route (.gpx).
So I use my routing navigation app

Harry

 

Mapping the location of individual trees may prove not accurate enough to actually use: GPS for citizens has been degraded to an accuracy of around 20/30 feet.

And it will only get worse, since GPS satellites are slated to start falling out of the sky in 2 years time (and the US have no replacement plan: they're broke). Already the system runs on only 25 satellites (instead of 28) because they go on the blink one by one and all the spare satellites (4) have already been used.

The good news is that the EU (Galileo), Russia (Glonass), and Chinese (Baidu) are busy setting up their own satnav systems independent from the US' GPS. They ought to be online in 2 years.

Tiny problem: our iPhones and smartphones can't handle other satnav systems (yet). Afaik the just announced Samsung Note is currently the only smartphone on the market that can handle another satnav system: namely Glonass.

Japan, India, Brasil, and Australia are also seriously contemplating their own satnav systems.
Anything to not be dependent on US' manipulated GPS anymore.