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.
BVoIP - BVoIP allows to easily add Cloud & On-Premise VoIP PBX to the product offering without having to re-invent the wheel or add another layer to the daily operations..
Dropbox - Online Sync and File Sharing
Windstream Holdings - Windstream Holdings is a scalable cloud-based business phone solution that provides complete and unified communication applications to businesses of all sizes.
Google Drive - Access and sync your files anywhere
Cebod Telecom - Cebod Telecom is a flexible, cost-effective VoIP business phone service solution used by various businesses and industries such as real estate, healthcare, tax office and marketing etc.
Mega - Secure File Storage and collaboration