A nice addition to my portable electronics test kit. Seems to work well. Interestingly (perhaps strangely) enough it does draw a good amount of power--my Apple shut down the USB port a couple times and I found myself needing to drive it off a wall wart.
Update: The cause of the power use seems to be a short on the USB connector on the board. I can even hear small popping sounds from the connector area when it is plugged in. I have had a string of communications back to the maker in which I was asked to try different cable and different power adapters. I did this twice. The issue is still not resolved. The maker explains that he checks each one before sending and seems to indicate he believes the problem occurred in either shipping or through "mishandling." Communications on getting this resolved has been slow and continues. I'll provide another update if it is eventually resolved. Also, since receiving it originally took awhile and I didn't immediately jump on trying to resolve the issue since I believed it was "normal" to draw that much power, I missed the 30-day warrantee window. So, my recommendation is to double-check yours as soon as you get it making sure that the USB connector is secure. The few times it functioned correctly, it seems to be a good portable tester. Unfortunately, for me it is currently a (fairly expensive) broken board in my test box.