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.
Dropbox - Online Sync and File Sharing
TeamLogger - Simple, employee time-tracking software with automatic screenshots and activity level monitoring. $1 / User / Month.
Google Drive - Access and sync your files anywhere
Monitask - Employee Monitoring Software with Screenshots, Internet, Activity and Time Tracking
Mega - Secure File Storage and collaboration
Time Doctor - Time Tracking and Time Management Software that is accurate and helps you to get a lot more done each day.