MM Tracker, if it works on your device OK (check out with MM Tracker Free) will load lots of map files from other sources so hopefully that will help you.
NavDroyd and MapDroyd let you download maps to your device for 'offline' use
There are also a bunch of toher bits of software that is probably good for more diagnostics or just showing where you area
I don't have a tablet or anything yet but I do have an Android Mobile Phone, which is a bit slow at the moment