One of the better ones I've tested so far... – World Geo Wiz Review
Still not the most interesting app in the world, but you do get all categories for free, and it's a very straight-forward type of quiz. Categories include Flags, Currency, Capitals etc.
One of the few I'm keeping out of the dozen I've tested today. :-)
Review by mcdisney2001 on
World Geo Wiz.