Question

If the class TestClass is not extending any other class like Activity. It would be a helper class. In this case is it required to register this class in the manifest file? Or because this class is not displaying a UI or extending any UI class, can I leave it out of the manifest without causing problems?

 <activity android:name=".TestClass"> 
        <intent-filter >
            <action android:name="com.example.TESTCLASS"/>
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </activity>

Answer 1

You do not need to register a helper or utility class in your manifest.

Only the components listed here, namely Activities, Services, Providers and Receivers need to be registered.

Other classes like helper classes or classes extending SQLiteOpenHelper etc. need not be included in the manifest.