BlueMessenger 1.0 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this free software for Mac is UUSO Inc.
The software lies within Communication Tools, more precisely Social & Blogging. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
BlueMessenger is an instant messenger app based on Bluetooth for you to chat with other people nearby. With this tool installed on their devices, people can chat with each other through a Bluetooth channel, without the need of a WiFi or cellular connection. Currently, Blue-Messenger supports iPhone-to-iPhone and iPhone-to-Mac communication.
You may want to check out more software for Mac, such as Showit, Facebook for Adobe AIR or Facile, which might be similar to BlueMessenger.