Why the App is installed twice?

Question

When I run the Android App Studio, the cell is the App is "installed" twice: There are two apps one called "SplashScreenActivity" and other "Doctor Quiz" (my app), the two are equal. If I uninstall one, the other also uninstalls.
Why does this happen? How do I "install" just my app? (DoctorQuiz)

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.morais.daniela.doctorquiz" >     <uses-permission android:name="android.permission.INTERNET"/>     <provider android:authorities="com.facebook.app.FacebookContentProviderXXXX"         android:name="com.facebook.FacebookContentProvider"         android:exported="true" />     <application         android:allowBackup="true"         android:icon="@drawable/medicine_box_icon2"         android:label="@string/app_name"         android:theme="@style/AppTheme" >         <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/facebook_app_id"/>         <activity             android:name=".Activity.SplashScreenActivity"             android:configChanges="orientation|keyboardHidden|screenSize"             android:label="@string/title_activity_splash_screen"             android:theme="@style/FullscreenTheme">         <intent-filter>         <action android:name="android.intent.action.MAIN" />         <category android:name="android.intent.category.LAUNCHER" />     </intent-filter>         </activity>         <activity             android:name=".Activity.QuestionsActivity"             android:label="@string/app_name" >             <intent-filter>                 <action android:name="android.intent.action.MAIN" />                  <category android:name="android.intent.category.LAUNCHER" />             </intent-filter>         </activity>         <activity             android:name=".Activity.ResultActivity"             android:label="@string/title_activity_result" >             <activity android:name="com.facebook.FacebookActivity"                 android:configChanges=                     "keyboard|keyboardHidden|screenLayout|screenSize|orientation"                 android:theme="@android:style/Theme.Translucent.NoTitleBar"                 android:label="@string/app_name" />         </activity>      </application>  </manifest> 

Screenshot

Answer 1

The app is not installed twice. You are not looking at apps. You are looking at launchable activities, ones with this <intent-filter>:

        <intent-filter>             <action android:name="android.intent.action.MAIN" />              <category android:name="android.intent.category.LAUNCHER" />         </intent-filter> 

You have two activities with that <intent-filter>, and so you will have two activities in the home screen launcher. If you do not want both of those activities in the home screen launcher, remove that <intent-filter> from one of them.