Mumble - Mumble is an open source, low-latency, high quality voice chat software primarily intended for use...
Sync.com - Sync. com offers a backup tool and a file sharing service, rolled into one.
Discord - Step up your game with a modern voice & text chat app. Crystal clear voice, multiple server and channel support, mobile apps, and more.
Zoho WorkDrive - File storage & content collaboration tool for modern teams
RaidCall - Free & Light. Setting up is fast and easy; with no need to rent or set up servers. Low CPU usage and minimum memory footprint allows for smooth, uninterrupted communication. im. Group Communication.
kDrive - The most privacy-friendly online storage and file sync service. From 2 TB, hosted in Switzerland.