Free CloudFiles gives free trial for 14 days. After the trial expires, you will need to buy license at $5/user/month($3 for non profits) from the link given in app. You'll always have access to your uploaded files even if you choose to not buy a license.
With CloudFiles you can attach files to any salesforce object(standard and custom) from cloud storage like Google drive, Box, OneDrive. You can also upload to cloud storage right from salesforce and uploaded files are automatically linked to the object.
We show Salesforce accounts that are linked to Trailblazer.me and have the Manage Billing permission. If your account is missing, check that you connected the account to your Trailblazer.me profile. Then verify that you’ve been assigned the Manage Billing permission in the related org.