Neither ArcGIS Workflow Manager nor Microsoft Flow offers a free trial.
ArcGIS Workflow Manager is designed for Large Enterprises, Medium Business and Small Business.
Microsoft Flow is designed for Large Enterprises, Medium Business and Small Business.
Pricing for ArcGIS Workflow Manager Starts at $600/Year whereas for Microsoft Flow Starts at $15/User/Month.
Some top alternatives to ArcGIS Workflow Manager includes Process Street, Microsoft Flow, ProcessMaker, IBM Blueworks Live, IBM Business Automation Workflow, ProcessPlan, ProcessPolicy.com, Bautomate, Withprocess.com and BPMapp by 500apps.
Some top alternatives to Microsoft Flow includes VisionFlow, Zapier, Zoho Flow, ProcessMaker, Microsoft Power Automate, IBM Business Automation Workflow, BPMapp by 500apps, ZapUp by 500apps, Built.io Flow and Cflow.