Firemint's Real Racing 2 ($6.99 for iPhone and $9.99 for iPad) is arguably the best racing game in the App Store, and the bump up to 16 players for on-the-spot online races is one of the best enhancements of all. Players of both the iPhone and iPad versions of the game can link up for fluid races over Game Center, but we highly recommend honing your skills offline first!

Phone hopping sensation Doodle Jump ($0.99) takes on a new tenor as a competitive multiplayer experience, in which two players battle it out to last the longest on the tricky upward climb. Finding an opponent is a breeze in this hugely popular app, and when you dominate the competition (or vice versa), jumping into a quick rematch is no hassle at all.

Super Stickman Golf ($2.99, universal), Noodlecake's wildly addictive 2D take on golf is one of the best multiplayer games on both iPhone and iPad, thanks to a fast-paced approach that favors the quickest to sink his/her ball in the hole. The universal app lets players on either device link up in 2-4 player battles, and a recent update makes it easier than ever to find competition and get swinging.

Stunning swordfighting action game Infinity Blade ($5.99, universal) has been one of the App Store's more prominent successes, but it's no one-trick pony -- developer Chair Entertainment has been consistently updating the game, and it now features online multiplayer battles. Strategic swipes and defensive maneuvers (along with careful upgrades) determine your success in this intense affair.

Using your finger to slice flying fruit is one of the most engaging uses of the touchscreen, and thanks to a recent update, Fruit Ninja ($0.99 for iPhone and $2.99 for iPad) is now a competitive venture. In this tug-of-war battle, you'll earn points for slashing your own fruit or neutral pieces, and lose points for cutting your opponent's fruit. Slash smart and you'll take the title.

Beloved German board game Carcassonne ($9.99, universal) -- in which players lay land tiles and followers to earn points -- is one of the pricier games on this list, but it's also easily one of the best. Carcassonne's elegant universal design lets you play with up to four opponents, and the slick aesthetics deliver the tried-and-true board game experience when you're out and about.

MetalStorm: Online (free, universal) uses a free-to-play model with microtransactions, which means you'll either need to invest a ton of time or a little money to access the deeper content. But those looking for a quick aerial dogfight from time to time will find this to be a surprisingly polished option. It looks great and plays well, plus it's a universal app that lets you shoot down foes on either iDevice.

If you like match-three puzzle games but can't help but think they'd be better with a little more action (and role-playing elements), then Puzzle Quest 2 ($4.99, universal) is clearly designed with your tastes in mind. The online battles find you matching gems and icons to deliver fantastical attacks against opponents, though the game also includes a lengthy single-player campaign as well.

Rather than battling to see who can land the most planes, the online experience in Flight Control ($0.99 for iPhone and $4.99 for iPad) is more about teamwork, as each player controls a couple of distinct runways and helipads. If a differently marked plane or helicopter crosses into your airspace, simply guide it over to the next screen and let your partner handle the rest!

The official World Series of Poker app arrives with separate free apps for iPhone and iPad, and while you'll have to play offline a fair bit (or spend some real-world money) to earn enough chips for the tense online battles, poker diehards will appreciate the straightforward approach. Plus, the apps play nice together, so there's usually plenty of online competition.