Slack - A messaging app for teams who see through the Earth!

Zello - Zello's push-to-talk app redefines the walkie talkie. It's a great push-to-talk over cellular (PoC) alternative for businesses and organizations. Learn more about the best walkie talkie app in the market.

Skype - Stay in touch with your family and friends for free on Skype. Download Skype today to chat and call on desktop and mobile.

Walkie-Talkie.io - This completely free walkie-talkie app online allows you to communicate quickly and easily with your friends. Go to the same radio frequency, push to talk and that's it! There is also a mobile iOS version and always 100% free !

Microsoft Teams - Microsoft Teams provides the enterprise-level security, compliance and management features you expect from Office 365, including broad support for compliance standards, and eDiscovery and legal hold for channels, chats, and files.

NuovoTeam - NuovoTeam Push-to-Talk (PTT) App for Frontline Workforce.