Let’s look at what is going on OS-wise as you move between activities. First, when you click on the GeoQuiz app in the launcher, the OS does not start the application; it starts an activity in the application. More specifically, it starts the application’s launcher activity. For GeoQuiz, QuizActivity is the launcher activity.
When the New Project wizard created the GeoQuiz application and QuizActivity, it made QuizActivity the launcher activity by default.
Launcher activity status is specified in the manifest by the
intent-filter element in QuizActivity’s declaration (Listing 5.18).
QuizActivity declared as launcher activity (
<manifest xmlns:android="http://schemas.android.com/apk/res/android" ...