I've been trying to download apps from google play but each time I try my Mobile isn't listed amongst the devices , my previous mobiles are there , I've been going round in circles trying to suss it out but I'm no further forward ,my mobile I'm using now is a Nokia Lumia 520 , I've tried making a new google account but its still just the same , it doesn't show up, I've been in the device manager settings on the account but there's nothing there about adding a new device , any help on this would be appreciated, thanks