You may try mobileEcho to secure mobile file management. It's a comprehensive, secure solution for:
1) Accessing corporate content on file servers, NAS and SharePoint.
2) Sharing files and content with co-workers and with external parties such as customers, outside partners, and outside vendors (e.g. legal counsel, accountants, banks, etc.)
3)Syncing and sharing content across all of your devices – desktop, laptop, tablet and smartphone.
1) Accessing corporate content on file servers, NAS and SharePoint.
2) Sharing files and content with co-workers and with external parties such as customers, outside partners, and outside vendors (e.g. legal counsel, accountants, banks, etc.)
3)Syncing and sharing content across all of your devices – desktop, laptop, tablet and smartphone.
4) and so on
Check more here: http://www.acronis.com/enterprise/products/mobilecho/
This is a very important question and I believe that companies need to pay more attention to mobile device management.