A new geolocation app for the iPhone was released today called Rally Up. What differentiates Rally Up from the likes of Foursquare and Gowalla is that it has a strong focus on privacy and sharing content. Rally Up bills itself as “a social network for real friends” and its focus is on letting people share messages and photos with the people they trust.

To this end, Rally Up takes a very different approach to friends lists and friends management from other social applications. For instance, Rally Up doesn’t integrate with Twitter. What!? I hear you gasp. As the saying goes, “it’s not a flaw, it’s a feature.”

The point of Rally Up isn’t to create or tap into yet another social network, it’s to be able to be selective about who you share information with.

For instance, when you add a user as a friend, you have different options that control how information is shared with them and how information is received by them. This “slider” can be changed at will.

Here are your options:

• Real friends – These are people that you want to know about, meaning you will see their activity in your feed and get push notifications of what they are doing. So your boyfriend or girlfriend or your sister are the types of people you might put in this category.
• Feed friends – You’ll get updates from these individuals in your feed, but you won’t get push notifications. So your co-workers or your gym buddies might go here. You like to know what they are up to, but you don’t need to be alerted at all times.
• Lurk – This is a pretty cool option, it lets you see what your friend is doing but they won’t see your check-ins. Likewise, you won’t get any push notifications about them. So when you’re shopping for a birthday present for someone, you might want to put them in the Lurk category.
• Mute – OK, so you know that girl from high school that you kind of sort of remember but can’t really place who keeps friending you on Facebook and LinkedIn andFoursquare? You don’t want to be rude and might feel obligated to accept her as a friend, but you really don’t care about what she’s doing, nor do you want her to know what party you are going to. So mute her. She won’t see your updates and you won’t see hers. If you feel like unmuting later, you can always do so.

When it comes to check-ins, Rally Up has a lot more granularity in that regard too. For instance, you can designate locations as being private. That means that someone can see that you checked in at home, but “home” is never defined by a GPS location. Likewise, if you don’t want people to know details about where you work, you can designate your workplace as being private.

You can also create temporary locations for things like parties or conferences, without having to add those locations permanently to the database. At conferences especially, I always see tons of locations created for a specific event, only for those locations to be discarded after the event is over. Temporary locations make sense because you can check-in, but not clutter up the map for everyone else.

Rally Up also lets you use check-ins to let people know that you are headed to an event. So if you’re en route to a place, you can check-in and your friends can know you are going and then choose to meet you there.

Rally Up also lets you send personal messages and it integrates push notifications to give an SMS effect, but without charging for messages. That’s pretty cool.

Rally Up is free and is available for the iPhone now. As you can see from the above sceenshot, it’s also coming soon to the iPad.

If you want to take advantage of location-based social networks but want more control over who sees what, you might want to give Rally Up a shot.

What do you think about privacy when it comes to location-based networks? Let us know!