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
UpNote - A beautiful and clean cross-platform app for notes organizer
Google Drive - Access and sync your files anywhere
Notesnook - Notesnook is a simple and private note taking app that keeps your notes organized and synced on your phone, tablet and computer.
Mega - Secure File Storage and collaboration
todoZero - A powerful to-do and note app for busy people.