Help with app that opens other apps.

Hy , i am making portable speaker, that includes samsung galaxy 5 android phone.
I would like to create program with some buttons that opens other apps.
Just a simple app with my background and buttons.
I want that buttons to open Music Player, SoundWire, YouTube, File Manager, Settings, Android home screen and app for AUX.
I would also like to add button that turns WiFi on and off and one button that turns off the phone.

So basicly i would like to create some sort of mp4 player menu.

What is the easy way to do that?

Thanks for anwsers.