Downloading Nmeeting+ 5.2.1 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. This free Mac application was originally designed by NFON AG. The program lies within Communication Tools, more precisely Texting & Video calls. We recommend checking the downloaded files with any free antivirus.
From the developer:
Nmeeting+ is web-based management of web and HD audio conferencing. With this application, users of the NFON cloud-based telephone system can initiate ad hoc web conferencing during a live audio conference. The app interoperates with all HTML5 browsers (Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, Apple Safari) according to customer preferences.
You may want to check out more software for Mac, such as iChatMonitor, LopsterOSX or eToken, which might be similar to Nmeeting+.