More about the 5 Best Frontend Error Monitoring Tools.
Raygun is a full featured error tracking, performance, and APM tool that supports multiple platforms. TrackJS is a frontend error tracking service focused on developer debugging. TrackJS is inexpensive compared to Raygun.
With TrackJS, the focus is on errors occurring on the browser. Filtering is second to none, and the quick views of trending errors are helpful in digging past the 3rd party script noise. It filters down to the core issues.