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.
Zello - Zello's push-to-talk app redefines the walkie talkie. It's a great push-to-talk over cellular (PoC) alternative for businesses and organizations. Learn more about the best walkie talkie app in the market.
Dropbox - Online Sync and File Sharing
Walkie-Talkie.io - This completely free walkie-talkie app online allows you to communicate quickly and easily with your friends. Go to the same radio frequency, push to talk and that's it! There is also a mobile iOS version and always 100% free !
Google Drive - Access and sync your files anywhere
NuovoTeam - NuovoTeam Push-to-Talk (PTT) App for Frontline Workforce.
Mega - Secure File Storage and collaboration