Alps Potentiometer Type Multifunctional Operating Device Alps Push-Operated Switch,Wide Range Of Small Switches,Switches For Health Products,Low Profile Horizontal Operation Switch DA CHENG MINGHUA LIMITED , https://www.alpsswitch.com
Secret 2: Application is automatically installed 
Please rename the folder where you stored the apk program to start_apk_auto_install, then insert the USB device into your set top box, and all the Android apk programs in the start_apk_auto_install folder will be automatically installed. Support Q series single-core, dual-core, quad-core 1.0.6 or later firmware and H7 generation, second generation; H8 generation, second generation
Secret 3: Haimei Di's own memory cleanup program 
Hai Meidi Play Machine Collection
Secret 1: Engineering Mode Most of this friend should already know, quickly press up, down, left, right, right (arrow keys) + + - (volume key), and then come out a window, select OK on it Press and hold the home button in any window for about 3 seconds. A “Memory Usage†window will pop up. This page can be viewed in the background process, or you can end all background processes with one click. Looks like all models are suitable