Speaking of Marco, a few days ago he announced the open-source BugshotKit:
I’m starting the Overcast beta soon,2 and I wanted an easy way for my testers to report (non-crash) bugs and provide UI feedback. I also wanted a way to remind myself of UI or feature ideas easily, and I’ve occasionally needed to view the error console on the device when tracking down difficult bugs. BugshotKit addresses all of these: it’s an embeddable Bugshot annotation interface and console logger, invoked anywhere in your app by an otherwise unused gesture (e.g. a two-finger swipe up, a three-finger double-tap, pulling out from the right screen edge, etc.), that lets you or your testers quickly email you with helpful details, screenshots, and diagnostic information. Like Federico Viticci, I've tried BugshotKit in an app I'm beta-testing. It's a great idea that's well-implemented.