In android-N, this feature is included in it. check Number-blocking update for android N
Android N now supports number-blocking in the platform and provides a framework API to let service providers maintain a blocked-number list. The default SMS app, the default phone app, and provider apps can read from and write to the blocked-number list. The list is not accessible to other app.
advantage of are:
For more information, see android.provider.BlockedNumberContract
Update an existing project.
To compile your app against the Android N platform, you need to use the Java 8 Developer Kit (JDK 8), and in order to use some tools with Android Studio 2.1, you need to install the Java 8 Runtime Environment (JRE 8).
Open the build.gradle file for your module and update the values as follows:
android {
compileSdkVersion 'android-N'
buildToolsVersion 24.0.0 rc1
...
defaultConfig {
minSdkVersion 'N'
targetSdkVersion 'N'
...
}
...
}