Debuggify does much more than just tracking javascript exceptions through window.onerror.

For starters

- provide apis to track custom exceptions though try catch

- enables you to track errors for cross origin scripts

- support minified code through source map

- track the users so its easy to understand the impact of problem.

- supports modular logging same as server side

- track custom events

- search though the data

And much more

Check out documentation to know more

http://developers.debuggify.net/docs/#!/guide/simple

http://developers.debuggify.net/docs/#!/guide/advance