Zello PTT allows up to 300 users through its unique “channels” feature to simultaneously chat with real-time, high-definition voice transmission, effectively turning the phone running the application into a wide-reaching CB radio or walkie-talkie with no bandwidth restrictions.
Zello currently has over 40 million users worldwide. To date there are over 200,000 active Zello channels devoted to a variety of topics, with over 2 million users online a day. The app is popular in Europe, the Middle East, Mexico, and Latin America.
Like Voxer, Zello offers an Enterprise version of its application that can be utilized with a subscription fee, called Zello@Work. The Zello@Work service is provided in partnership with T-Mobile to provide PTT to some of its customers. The service is free for up to 5 users, with a small subscription fee beyond that.