Yes, both Sentry and Zenduty offer a Free Trial.
Sentry is designed for Large Enterprises, Medium Business and Small Business.
Zenduty is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
The starting price of Zenduty begins at $5/User/Month when Billed Yearly, while pricing details for Sentry are unavailable.
Some top alternatives to Sentry includes The Bug Squasher, Bugsnag, Zoho BugTracker, Rollbar, TrackJS, BugHost, Bug-Track.com, Disbug, Hawk and Crash Catch.
Some top alternatives to Zenduty includes Freshservice, PagerDuty, Opsgenie, VictorOps, AlertOps, Spike.sh, Rootly, Incident.io, StatusCast Incident Management, PagerTree and ResQ.