Supports local variables in stack traces, source maps. Also supports logging from many other languages. Free plan for <5000 events/month.
Sentry is a log aggregation tool open sourced on GitHub and available as a SaaS at GetSentry.com. Sentry was conceived in 2010 at Disqus and got the first paying customer in Feb...
Raygun keeps a watchful eye on your web and mobile applications and tells you when problems arise