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
Dood : The Puzzle Planet - A strategy puzzle game for the smart ones
Google Drive - Access and sync your files anywhere
Ordinary Puzzles - A minimalistic puzzle game inspired by Picross and Sudoku.
Mega - Secure File Storage and collaboration
Trikaya - Atmospheric first-person puzzle game