Last year, I was a big fan of the Great Little War Game for iOS -- what it lacked in the graphics department, it more than made up for in terms of tile-based tactical strategy (similar to Advance Wars or any of those other kinds of tactical war games). Now developer Rubicon has gone back to the well for a sequel, and the result is the Great Big War Game: It's exactly the same kind of title, only writ just a little larger.
The graphics are slightly improved (though Rubicon has stuck with the very stylistic little big-headed soldiers, as well as a goofy story), but the big draw here is all of the additions: There are 50 new levels, lots of new units and upgrades to play with, online multiplayer, and some extra map packs and add-ons to purchase if what's in the base game isn't enough for you. Rubicon has made an already good tactical strategy game better, and added a bunch of other little improvements and upgrades as well.
If you liked Great Little War Game, the Great Big version is a no-brainer, and even if you missed the first one (but the title sounds interesting to you), then Rubicon's latest is worth the purchase. You can get it as a universal version (without iCloud support, unfortunately) on the App Store right now for $2.99.