Yes, both GitHub and Airbrake offer a Free Trial.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Airbrake is designed for Large Enterprises, Medium Business and Small Business.
Pricing for GitHub Starts at $4/User/Month whereas for Airbrake Starts at $29/Month.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.
Some top alternatives to Airbrake includes Sentry, Bugsnag, Zoho BugTracker, Rollbar, TrackJS, BugHost, Bug-Track.com, Disbug, EventSentry and Crash Catch.