The interface is pretty solid, though there are some issues loading profiles. It doesn't give you everyone in your area but a cross-section. I didn't realize this until a friend of ours who bartends at one of our local haunts saw me on there but I didn't see him. Still it's pretty ok. It's quickly becoming more of a hook-up program in our area and less of a social networking program, but then again most gay social networking sites/programs/locations become sexualized easily. This one in particular since you can see how far people are from you. You can also favorite a boy, but he won't know you've done it and neither will anyone else. Moreover, while it stops transmitting your location when you close the program, it leaves your profile on the screen with your last known location and how long ago you were there. So there's a bit more potential for stalking.
Yesterday I went to Disney with some of our friends and we were using it to try and find the other gays at the park that day. It was a little drunken scavenger hunt while we were bouncing from wine tasting to wine tasting at EPCOT. Each time the programs said "0 Feet Away" we had three gays and a friendly lady scouring the nearby crowd for who it might be (there's a 20 foot margin of error). We had at least two sightings (one on a bench, and one was a bitchy manager yelling at another "cast member"). I also got a few chat messages and one hook-up request- lol, men. I do specifically list I'm in a relationship and not looking to hook-up but you can't blame a guy for trying, right?
Recently, I tried our another one called Purpll (http://www.rippll.com/purpll/). I'm still figuring out it's interface, but at least it's available on more than just the iPhone (I believe they may have an Android and a Blackberry version). It looks to allow messages but no chat function but you can load up more photos. It's sort of more like a mobile gay MySpace since it lets you have a friends list (and announces those friends to anyone clicking on your picture). So it plays out less like a hook-up program simply because it's a little more open than Grindr so the potential for drama is higher. Purpll also has a map function allowing people to see your location not just in how many feet you are from them, but on a google-map type app which is a little scary. However the map is only detailed if the two guys have friended each other. Still, potentially a creepy addition.
So as not to post pictures of the guys in my area on the internet I'm not giving you screen shots, but click the above links to have a look.
My friend and I are still trying to figure out if it's fun or creepy but either way, it's where we're headed I guess.
And now- something amusing for you.