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
Trivia Crack - Produced by Etermax, Trivia Crack lets players answer trivia questions and compete against other people on mobile devices.
Google Drive - Access and sync your files anywhere
QuizUp - QuizUp gives you the opportunity to test your trivia skills against friends and strangers throughout the world.
Mega - Secure File Storage and collaboration
Akinator - Akinator is an entertainment app that acts like a digital genie that can read your mind. The game will ask you a few questions about the character you have chosen, and it will attempt to guess the character from your provided answers.