1. 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.

  2. Acuity Scheduling

  3. Sync. com offers a backup tool and a file sharing service, rolled into one.

  4. Matrix is an open standard for decentralized persistent communication over IP.

  5. WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.

  6. Open source interoperable collaboration app.

  7. A messaging app for teams who see through the Earth!

  8. Fast, simple & secure messaging. Privacy that fits in your pocket.

  9. Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.

  10. Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.

  11. Secure access, sharing & file storage

  12. Google Drive is a personal cloud storage service from Google that lets users store and synchronize digital content across computers, laptops and mobile devices, including Android-powered tablet and smartphone devices.