AirBrake

Airbrake is the leading exception reporting service, currently providing error tracking.
HoneyBadger

Exception, uptime, and performance monitoring for Ruby.
Rollbar

Rollbar collects errors that happen in your application, notifies you, and analyzes them so you can debug and fix them. Ruby, Python, PHP, Node.js, JavaScript, and Flash libraries available.
Dynatrace

Cloud-based quality testing, performance monitoring and analytics for mobile apps and websites. Get started with Keynote today!
Stackify

Stackify is the only developers-friendly solution that integrates error and log management with application performance monitoring. Code more support less. Start your free trial now.
BugSense
The best real-time bug tracking service for Android, iOS & WP7.
S3stat

S3stat is a service that takes the detailed server access logs provided by Amazon’s CloudFront and Simple Storage Service (S3), and translates them into human readable statistics, reports and graphs.
BugSnag

Not all bugs are worth fixing. Prioritize and fix software bugs that matter while improving software stability with every release.
OverOps

Know why Java code fails in production. Get the full Java source code and variable state for every error. Reproduce and Fix critical issues in seconds.
Invoicera

Invoicera™: World’s most powerful online invoicing & billing software trusted by millions of users globally.