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.
chitchat - Chat Room with Selfies and Pagers (yes, pagers!)
Dropbox - Online Sync and File Sharing
Chalk - Chalk is a calculator that tries to do right what others do wrong.
Google Drive - Access and sync your files anywhere
Twist - Check fewer notifications, do more meaningful work. Twist is the team communication app for calmer, more organized, and more productive teamwork.
Mega - Secure File Storage and collaboration