the buildserver works as expected currently. When scanning a QR-Code it takes about 2 minutes to download a game like chicken outbreak, depending on your Internet Connection (10mbit for me at the Moment on my phone via WLAN). The Installation itself can take up to a few minutes, depending on the device (Nexus 7 ~3 minutes). You should check if you are allowed to install unsigned apks in your developer settings on the phone! Using Eclipse or Monitor or the adb you can check the log of your phone and see if there might occur any unusual behaviour.