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.
Jostle - A new kind of employee intranet that drives engagement & workplace culture. Achieves social participation in work relevant way. Participation rates are over 85%.
Dropbox - Online Sync and File Sharing
MS SharePoint - Share, organize, and discover information with Microsoft SharePoint. Learn about SharePoint Online, OneDrive for Business, and Apps for SharePoint
Google Drive - Access and sync your files anywhere
Simpplr - Simpplr’s social intranet offers powerful tools that ensure every employee is aligned and working toward common goals.
Mega - Secure File Storage and collaboration