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
WhatsPlay - Your event in real time
Google Drive - Access and sync your files anywhere
Phorevr - Photo storage with NO subscription.
Mega - Secure File Storage and collaboration
Rompolo - Create and share digital albums for events via QR codes or links. Upload photos, enjoy interactive walls, and relive memories on one platform.