Yes, both OmniFocus and nTask offer a Free Trial.
OmniFocus is designed for Large Enterprises, Medium Business and Small Business.
nTask is designed for Individuals, Freelancers, Medium Business and Small Business.
The starting price of OmniFocus begins at $9.99/Month, while pricing details for nTask are unavailable.
Some top alternatives to OmniFocus includes Todoist, Wrike, Smartsheet, Asana, ProWorkflow, nTask, Taskworld, TickTick, Today, MeisterTask, ClickUp and StickyList.
Some top alternatives to nTask includes Quickbase , Smartsheet, ClickUp, Zoho Projects, Wrike, TeamGantt, monday.com, Asana, Teamwork, ProjectManager.com, Microsoft Project, Trackboard, Quick Base, Today, MeisterTask and Height.