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.
QuoteWerks - Create professional quotes & proposals in minutes with QuoteWerks® - the Market Leading quoting software solution (CPQ) that integrates with your CRM and Accounting to create a seamless sales process.
Dropbox - Online Sync and File Sharing
PandaDoc - Boost your revenue with PandaDoc. A document automation tool that delivers higher close rates and shorter sales cycles. We've helped over 30,000+ companies.
Google Drive - Access and sync your files anywhere
ConnectWise Sell - Connectwise Sell is a Quote and Proposal Software with high quality, accurate quotes and attractive proposals.
Mega - Secure File Storage and collaboration