iPhone owners can finally join their Android chums in wandering about European cities, phone in hand, searching for landmarks that have been designated virtual Ingress portals.

A game by Google's Niantic Labs, Ingress has been around on Android for a while, but has now launched for iOS for the first time.

The game uses the geo-location technologies on smartphones to know where the user is in the real world and guides them to nearby spots that have been assigned as virtual portals. The "agent" must then either capture or control the portal using the app and effectively help either the Enlightened or Resistance factions for overall control in the worldwide battle.

The Enlightened team's plan is to seize the power that they emit, while the Resistance defends the portals so they don't get into the wrong hands.

Hacking is done through the game application and there are extra tools and items to be gained from encountering portals.

Ingress has been running for six months and has become something of a cult hit. So far agents around the world have made more than 22 million in-game actions. The app being released for iPhone could see that expand dramatically.

You can download it from iTunes for free now.