Nomadesk
Nomadesk offers file sharing and synchronization software that lets you access, share, sync, and secure your files anywhere—online and offline. The solution works almost identically to Dropbox, but is specifically designed for the business market. Nomadesk creates a virtual hard drive in the cloud and on your workplace's local hard drive. This allows you to store unlimited files in the cloud and view, edit, and share them locally on all your devices, both internally and externally.
SimplySo
SimplySo enables companies to collaborate more effectively through social interaction and easier information retrieval. It optimizes the use of the intelligent features of Office 365 applications such as SharePoint, OneDrive for Business, Delve, and Newsfeed. With SimplySo, employees can effortlessly share files. Furthermore, SimplySo promotes social interaction between colleagues by making it incredibly easy to post messages, images, and/or documents to a timeline, or by commenting on or liking colleagues' posts.