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.
Padlet - Visual boards for organizing anything.
Dropbox - Online Sync and File Sharing
Quizalize - Quizalize is a leading web-based and mobile-based classroom application that delivers the best and easiest way to differentiates your teaching.
Google Drive - Access and sync your files anywhere
Popplet - Popplet is the simplest application to capture and organize your idea.
Mega - Secure File Storage and collaboration