Zirkapp

Zirkapp lets you communicate with others who are close by. You don't need to be friends, followers, or anything like that; you just have to be close enough to use the app. (Your actual location is never revealed, though.)

With Zirkapp, you can post your zimess anytime, comment on other zimess or posts, and have private chats with other users online. You just have to be close to whoever you're talking to, i.e. within five kilometers.

In the Zirkapp settings, you can change your avatar, choose a new name, enable or disable notifications, set the distance of your zimess, etc. You can also register using Twitter, Facebook, or an email account.

Zirkapp is an interesting social app... as long as there are people using it. It could be a great app, of course, but there have to be a lot of people who download it and use it regularly.