Pick a side, iPhone users.

The augmented reality game "Ingress" is now available for Apple devices, meaning you can join millions of Android-toting players worldwide fighting for the Resistance or the Enlightened. The teams, one blue and one green, do virtual battle over local landmarks -- sort of like a high-tech version of capture the flag.

A bunch of local players were kind enough to let me tag along earlier this year for a story about this game happening all around us. It comes with an elaborate sci-fi backstory, but most players I talked to seemed most interested in the social side of the game.

Niantic Labs, a start-up within Google, built incentives into the game so that players would meet each other and go exploring together.

"So much tech pulls you into these online networks, and games in particular really suck you into an alternative reality," said John Hanke, a Google vice president and founder of Niantic. "Ingress is a reason for people to get together."

In a Google Plus post announcing the release of the iOS app Monday, one of the game's characters urged more seasoned players to help Apple users get started: "New Agents will look to you for leadership. Stand with them. Prepare them. We do not know what comes next, but we know how to face it. Together."

(Photo above: James Misuraca and Fe Strait ate dinner with fellow Ingress players before going out to the Minneapolis Sculpture Garden to claim landmarks for the Enlightened team. Jason Heger displayed the Ingress app on his smartphone. By Jim Gehrz, Star Tribune.)