Yes, both Userback and Backlog offer a Free Trial.
Userback is designed for Individuals, Freelancers, Medium Business and Small Business.
Backlog is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for Userback Starts at $14/Month when Billed Yearly whereas for Backlog Starts at $29.16/Month when Billed Yearly.
Some top alternatives to Userback includes Backlogs, Backlog, ReportBugz, Buglog, Usersnap, Ybug, Bug-Track.com, Disbug, Feedback Monkey and Toybox.
Some top alternatives to Backlog includes Quickbase , Smartsheet, ClickUp, Zoho Projects, Jira, Wrike, TeamGantt, FogBugz, Teamwork, ProjectManager.com, Trackboard, TaskBranch, Quick Base, TestRail, Height and Project Insight.