I get down to:
Install SmartApp...Click the Discover button. You'll probably have to hit refresh a couple of times to get your device to show up. If it doesn't show up make sure you're running an up-to-date version of the webapp.
I get: Select device(s) (0 found). Clicking Refresh is not helping. I have WebApp v0.8.0-8-g57438d1. I tried Googling and came up empty. I deleted what had been accomplished in the API under SmartApps up to that point and tried again with the same result.
Unfortunately, my "expertise" ends there.

Bob