U.GG 
Icy Veins 
Arcade Cloud 
EV.IO 
Luminosity Lux Touch and Lux DLX Updated
Lux Touch and Lux Dlx were a couple of the first Risk type games on the App Store. Updated today, they now include updated graphics and animation and new game modes. Both great options, Lux Touch is sort of a light version of Lux Dlx which has more maps to play. Give them a shot!
Jeff Scott
Jeff Scott is the founder of 148Apps and an app obsessed writer who loves talking apps, games, and the business around them. He knows what real football is, but still insists on calling it soccer.