Whoa! The cheapest Airbrake account costs $79! Are there alternatives to Airbrak & Exceptional?
Why? Well, it's practically useless outside of Ruby. The UX assumes Rack/Rails-isms, so the experience is weird for Javascript errors. Beyond that, stack traces aren't good enough to debug many issues; you need logging integration. This is especially true for minified javascript.
If you don't like something about it, I'm always happy to accept pull requests :)
You missed the small link at the bottom of the pricing grid
It's compatible with the Airbrake API, so you just need to configure the Airbrake Notifier gem to point to your Errbit instance.
Errbit (https://github.com/errbit/errbit) is an open source and free alternative, which is self-hosted. It's also compatible with the Airbrake API.
It's easy to set up in a few minutes, either on heroku, or on your own server. As well as being free, you can store your potentially private data in-house, and customize and integrate it as much as you want.