NextPlane - NextPlane offers cloud-based, scalable unified communications federation service for the enterprise.
Sync.com - Sync. com offers a backup tool and a file sharing service, rolled into one.
Voxer - Turn your phone into a Walkie Talkie. Don't waste time on phone calls and voicemails.
Zoho WorkDrive - File storage & content collaboration tool for modern teams
Sameroom - Chat interoperability-as-a-service
Yandex.Disk - Files on Yandex.Disk won't get lost if your phone or computer breaks.