Urban Airship api provides you better way to implement push notifications and also provide you facility to send messages on production without sending it to live users so you can even test in production phase.

This api supports gcm and amazon push notification services.

Here is the example to show how can we send push notifications using GCM services :

1 . Include urban maven repository and dependencies like this :

repositories {
    maven {
        url  "https://urbanairship.bintray.com/android"
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:23.3.0'
    compile 'com.android.support:design:23.3.0'

    compile 'com.urbanairship.android:urbanairship-sdk:6.2.+'
    compile 'com.android.support:cardview-v7:23.3.0'

    compile 'com.google.android.gms:play-services-location:8.4.0'
    compile 'com.google.android.gms:play-services-gcm:8.4.0'
}

 Please note that sometimes you can face error  like no gcm service enabled for messaging like this so change the 8.4.0 to 7.5.0 .

2. Verify the applicationId :

defaultConfig {
    applicationId "com.example.rohitpuri.myurbanapplication"
    minSdkVersion 15
    targetSdkVersion 23
    versionCode 1
    versionName "1.0"
}

3. Now go to urban web ui to create and configure your android app :
    
  Go to https://go.urbanairship.com and create new app then fill form to enter app name, icon, production status, select platform like android or ios etc and save form.

4. Download your airoushconfig.properties file and save it to src/main/assets folder.

Note - also remember to add sender id in this config file , this sender id will generate from gcm dashboard.

5. Now create a class extends Application and in onCreate create airship class to enable user notifications in app like this :

public class CustomApplication extends Application  {

    @Override
    public void onCreate() {
        super.onCreate();

        UAirship.takeOff(this, new UAirship.OnReadyCallback() {
            @Override
            public void onAirshipReady(UAirship airship) {

                // Enable user notifications
                airship.getPushManager().setUserNotificationsEnabled(true);
            }
        });
    }
}

6. Add the GCM Sender ID airshipconfig.properties

# GCM Sender ID
gcmSender = #########

7. build your project then from urban web ui there is an option to send message where you can enter text and can send push notification messages to registered applications.