Yes, both Overflow and Flow offer a Free Trial.
Overflow is designed for Large Enterprises, Medium Business and Small Business.
Flow is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Overflow Starts at $12/User/Month when Billed Yearly whereas for Flow Starts at $6/User/Month when Billed Yearly.
Some top alternatives to Overflow includes Miro, FigJam, SmartDraw, Gliffy, Microsoft Visio, Creately, EDraw Max, FlowMapp, Isoflow, Quick Diagram, diagrams.net and Flow.
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.