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
Pillow Whisper - Pillow Whisper is a social app to help you share your views and ideas on Twitter to share them with the outside world without having to access the Twitter app.
Google Drive - Access and sync your files anywhere
Birdy for Twitter - Birdy for Twitter app lets users collect the desired twitter profiles and make a list to get new tweets from them right at their fingertips.
Mega - Secure File Storage and collaboration
I’m XAM - I’m XAM is a social app by I’m XAM LLC that enables users to take the private messaging experience to a whole new level by sending text messages to their friends from all around the globe.