1. Download APK first, then copy to your Android device's SD card

2. Install APK, DO NOT open app

3. Download obb files, then rename to 'main.27.com.entwell.rk_org.obb'

4. Copy obb file to /SDCARD/Android/obb/com.entwell.rk_org/main.27.com.entwell.rk_org.obb