Yes, both Trello and Mockflow offer a Free Trial.
Trello is designed for Individuals, Freelancers, Large Enterprises, Medium Business and Small Business.
Mockflow is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Trello Starts at $5/User/Month when Billed Yearly whereas for Mockflow Starts at $14/Month when Billed Yearly.
Some top alternatives to Trello includes Smartsheet, Miro, Process Street, Wrike, Notion, Freshbooks, Jira, Basecamp, Zoho Projects, monday.com, Asana, Teamwork, ProjectManager.com, Microsoft Project, Worksuite, Trackboard, Quick Base, Todoist, ClickUp, Resource Guru and Height.
Some top alternatives to Mockflow includes Miro, NinjaMock, Balsamiq, Axure RP, Wireframe.cc, Mockplus, Inspireframe, Claritee, Stage, Zen Wireframe and Lightning Builder.