Yes, both Box and Flow offer a Free Trial.
Box is designed for Large Enterprises, Medium Business and Small Business.
Flow is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Box Starts at $5/User/Month when Billed Yearly whereas for Flow Starts at $6/User/Month when Billed Yearly.
Some top alternatives to Box includes CollaborateCloud, Microsoft SharePoint, Dropbox Business, FileCloud, ownCloud, Microsoft OneDrive for Business, Dropbox Professional, Citrix Content Collaboration, Genialcloud Facsys and Box Skills.
Some top alternatives to Flow includes Quickbase , Smartsheet, ClickUp, Zoho Projects, Wrike, TeamGantt, Teamwork, ProjectManager.com, Microsoft Project, ProWorkflow, Trackboard, TaskBranch, Quick Base, Height, Task Flow and Project Insight.