I got a dev phone and found the UI is different from the one I saw in the vedio on youtube. Now I have some questions: 1. How could I install apps? Because there's no drop-down menu so I cannot enter USB mode. 2. Where can I find apps to download? 3. When pressing volume- and power button, the phone seems enter the flashing mode. It shows "cable is connected" and "Do not turn the phone off while downloading" but actually it downloads noting. 4. Why this phone's UI is different to the one I saw before?