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
FileInvite - Stop chasing your clients for documents! Easily request files, documents, forms & signatures from your clients – set a due date and save hours as your requests are returned to you effortlessly.
Google Drive - Access and sync your files anywhere
iDeals Virtual Data Room - iDeals Virtual Data Room is a tool that provides secure access to large amount of confidential documents and can view, analyze and collaborate in a protected environment.
Mega - Secure File Storage and collaboration
Clinked - White-label Client and Team Workspace