Ah well, perhaps I misunderstood your original post where you mentioned
an iPad. I'm not an Apple person but I do know someone who uses the app
on an iPhone. This app is in all respects the same as the one I use on
my Android phone. It also appears to be the same as the one available
for an iPad - see
http://www.memory-map.co.uk/ which says it's available
in the App Store.
I see now, though, that you mention that you want to "use the maps in my
pc". The Memory Map software which is available (for free) for your PC
is a very different beast to the apps available for Android and iPhone
and, IMO, it is a fine piece of software offering many more features
than the 'app'. Not least is the ability to produce maps from any image
file and calibrate them yourself.
Of course, I have no idea where your qc3 files came from. Presumably, if
you bought them from MM then they will have been supplied with licences
for use on one or more devices. If they are from some other source -
maps that you've maybe drawn and calibrated perhaps, or ones such as the
Spanish IGN ones that I mentioned - then it's likely that you will need
to buy a '3rd party licence' from MM. This is true whether you want to
use them with the PC software or with the app for iPad/iPhone/Android.