Yes, both GitHub and Fronter.io offer a Free Trial.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Fronter.io is designed for Large Enterprises, Medium Business and Small Business.
Pricing for GitHub Starts at $4/User/Month whereas for Fronter.io Starts at $19/Month.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.
Some top alternatives to Fronter.io includes Front, QuickReviewer, Hightail, Coment, MockVisual, Featurebase.app, fdbck.io, Superflow and Feedback Monkey.