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.
WP SlackSync - Synchronize Slack channels + chats with your Wordpress site
Dropbox - Online Sync and File Sharing
yaP - Innovative digital banking. Sign up to YAP and get a digital banking account – No hidden fees, no minimum balances, and no paperwork.
Google Drive - Access and sync your files anywhere
Slackin - Create your own public Slack chat community
Mega - Secure File Storage and collaboration