AndroidManifest.xml

Declares your app's compatibility with different Android versions

<manifest xmlns:android="http://schemas.android.com/apk/res/android" ... >    
<uses-sdk android:minSdkVersion="8" android:targetSdkVersion="19" />    
...</manifest>

You should always set the android:targetSdkVersion as high as possible and test your app on the corresponding platform version.