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
instashare - Share your photos to instagram from your mac
Google Drive - Access and sync your files anywhere
BlackHole File Transfer - Blockchain-based file transfer. Designed for everyday use.
Mega - Secure File Storage and collaboration
ToffeeShare - Send files of any size directly from your device, without ever storing anything online.