Yes, both Slenke and Notion offer a Free Trial.
Slenke is designed for Large Enterprises, Medium Business and Small Business.
Notion is designed for Individuals, Freelancers, Medium Business and Small Business.
Pricing for Slenke Starts at $15/User/Month when Billed Yearly whereas for Notion Starts at $4/Month when Billed Yearly.
Some top alternatives to Slenke includes Smartsheet, Miro, Process Street, Wrike, Notion, TeamGantt, monday.com, Teamwork, ProjectManager.com, Microsoft Project, ProWorkflow, Projectworks, Trackboard, Quick Base, ClickUp and Project Insight.
Some top alternatives to Notion includes Jira, Knote, Trello, Confluence, Asana, Easynote, ClickUp, TWiki, MeisterNote and Zenkit Hypernotes.