Unity 2018 project for Android

I need a simple project shat just shows us how it is done. A button, and then some c# code: Button 1: Show us how to call a file selector on Android. Button 2: Show us how to record, save and replay a sound file. Button 3: Show us how to call Teamviewer from a Unity project. Button 4: Show us how to call the contacts and select one. Button 5: Show us how to display a map, locate me via GPS and let me change my position if it is not quite correct. All in Unity for Android. Need not be pretty, should be simple, just to show us how to do it. Further questions may follow.