Yes, both OmniFocus and ProWorkflow offer a Free Trial.
OmniFocus is designed for Large Enterprises, Medium Business and Small Business.
ProWorkflow is designed for Large Enterprises, Medium Business and Small Business.
Pricing for OmniFocus Starts at $9.99/Month whereas for ProWorkflow Starts at $9/User/Month when Billed Yearly.
Some top alternatives to OmniFocus includes Todoist, Wrike, Smartsheet, Asana, ProWorkflow, nTask, Taskworld, TickTick, Today, MeisterTask, ClickUp and StickyList.
Some top alternatives to ProWorkflow includes Quickbase , Smartsheet, ClickUp, Zoho Projects, Wrike, TeamGantt, Asana, Teamwork, ProjectManager.com, WorkflowMax, ProProfs Project, Projectworks, Taskworld, WirTask, Quick Base and Flow.