Application usage and crash statistics for an offline program

I would like to monitor usage statistics and send crash logs for my .NET application. The application will be run offline on a laptop for most users hence they may not have an internet connection at that time.

Can someone recommend a usage/crash statistics framework for monitoring a .NET application that has can cache reports and send when there is an internet connection later on?

Even better would be a testflight framework for beta testing that encorporates this, offline caching of reports however is a must.