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.
Planning Poker - Open source implementation of planning poker game (collaborative online estimation/voting tool).
Dropbox - Online Sync and File Sharing
Firepoker - Agile Planning Poker powered by Firebase and AngularJS
Google Drive - Access and sync your files anywhere
Taiga - Project management platform for agile developers & designers
Mega - Secure File Storage and collaboration