We know that debugging AppHarbor applications is sometimes a pain because exceptions and stacktraces can be hard to come by. To help you out, AppHarbor now logs all
WebRequestErrorEvents surfaced by ASP.NET Health Monitoring. Errors for your applications are available from the individual application pages by following the "Errors" link.
AppHarbor application-error logging is not meant as a substitute for full-on event-logging and monitoring add-ons like New Relic and Hoptoad, but it should work great for debugging deployment problems when moving applications to AppHarbor.