I've written only apps for Chrome, not extensions, but the process is nearly identical. If you go to Wrench > Tools > Extensions you can load the directory you'

I've written only apps for Chrome, not extensions, but the process is nearly identical. If you go to Wrench > Tools > Extensions you can load the directory you're working in. I suppose you can self-publish extensions with the experimental APIs but I doubt many people play around with chrome.experimental. I played around with chrome.experimental.tts a bit, but not knowing if the feature will be killed or promoted is reason enough not to waste too much of your time.