Yes, both Overflow and EDraw Max offer a Free Trial.
Overflow is designed for Large Enterprises, Medium Business and Small Business.
EDraw Max is designed for and Small Business.
Pricing for Overflow Starts at $12/User/Month when Billed Yearly whereas for EDraw Max Starts at $99/Year.
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 EDraw Max includes Miro, FigJam, MindManager, SmartDraw, Gliffy, Microsoft Visio, Creately, Lucidchart, DrawSQL, Quick Diagram, diagrams.net and yEd Graph Editor.
