I just received a Xiaomi Mi3, chinese Android phone, for a work project, and wanted to put it in developer mode. Most guides are for Android 4.2 and 4.3, but this one had version 4.4.2. The guides advice to tap 7 times the Android version, but that will just give you a really weird easter-egg. Instead, tap the build version seven times, and it will go into development mode.