Android : Android app not showing on my device. No Launcher Activity Found

I am simply following the Android Developer training guide, and I am already running into troubles on the second step.

http://developer.android.com/training/basics/firstapp/running-app.html

I followed the guide (I don't even have to do anything..) and clicked on Run, selected my Galaxy S4 from the screen, and clicked okay. I get the following error

[2014-07-06 19:56:27 - MyFirstApp] Android Launch!
[2014-07-06 19:56:27 - MyFirstApp] adb is running normally.
[2014-07-06 19:56:27 - MyFirstApp] No Launcher activity found!
[2014-07-06 19:56:27 - MyFirstApp] The launch will only sync the application package on the device!
[2014-07-06 19:56:27 - MyFirstApp] Performing sync
[2014-07-06 19:56:27 - MyFirstApp] Automatic Target Mode: Unable to detect device compatibility. Please select a target device.
[2014-07-06 19:56:31 - MyFirstApp] Application already deployed. No need to reinstall.
[2014-07-06 19:56:31 - MyFirstApp] \MyFirstApp\bin\MyFirstApp.apk installed on device
[2014-07-06 19:56:31 - MyFirstApp] Done!

I honestly have no idea what I am doing wrong, as I have absolutely no experiences with android.

The following is my AndroidManefiest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myfirstapp"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
    </application>

</manifest>