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 Backlog, ReportBugz, Buglog, Usersnap, Ybug, Bug-Track.com, Disbug and Toybox.
Some top alternatives to Backlog includes Wrike, Smartsheet, TeamGantt, Teamwork, ProjectManager.com, Trackboard, TaskBranch, TestRail, Height and Project Insight.