For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
Voxer - Turn your phone into a Walkie Talkie. Don't waste time on phone calls and voicemails.
Dropbox - Online Sync and File Sharing
NextPlane - NextPlane offers cloud-based, scalable unified communications federation service for the enterprise.
Google Drive - Access and sync your files anywhere
Sameroom - Chat interoperability-as-a-service
Mega - Secure File Storage and collaboration