In a blog post today, location-based app foursquare (yes, intentionally no capital F apparently) announced a new feature specifically for iOS5 called ‘Radar’.

A lot of app makers are creating new features that take advantage of all of Apple’s new iOS5 functionality, and foursquare was quick out of the gates to announce its own. The update for foursquare is not on the Apple App Store yet, as we’re sure that the company is inundated with new app updates for today’s iOS5 public launch.

The company said this about Radar:

The initial vision for foursquare centered around one question: can we build something to help make the world easier to use. Until now, we’ve focused around sharing what you’re doing and building expertise, with features like checking in, tips and recommendations. Today, we’re super excited by what some of iOS 5′s newest features allow us to do. Specifically, say hi to foursquare’s ‘Radar,’ a huge step in the evolution of the foursquare vision.

Now, if you follow a list, like the 101 Best Dishes of 2011, foursquare will let you know when you’re next to one. Or you save that yoga studio to your To-Do List (because you really want to try it); we can remind you when you’re close. Or, better yet, if you’re driving home and three of your friends are getting together nearby, we’ll tell you so you can meet up. The app doesn’t even have to be open, it just works. We call it foursquare Radar, because it finds things nearby that you normally wouldn’t know about.

radar blog foursquare announces social location feature called Radar for iOS5

Telling you that you’re close to a location is a great thing for users of the app, but more importantly it’s a perfect way for merchants to gain exposure about their offerings and deals. For example, if you’re at dinner, you can be notified that a few of your friends are at a near-by bar for a night-cap. This type of functionality is something companies have tried to get right for a long time. foursquare has owned the check-in market, despite Facebook’s launch of its “Places” offering.

On a side note, the company has also changed a color that we’re familiar with. The familiar purple in the app and icon has been changed to green.

Real-time deals and opportunities are important because people increasingly have their smart phones with them at all times. The only issue about location services that are “always on” is that it tends to use up more of a smartphone’s battery, especially the iPhone 4 – then there’s the privacy issue for people who have forgotten. The iPhone 4S could have better standby time, but we won’t know for sure until we have one in our hands. With Radar, foursquare is primed to control real-time location opportunities for users.