android { 
         ..... 
         defaultConfig{ 
         targetSdkVersion 28 
         } 
         compileOptions { 
                 sourceCompatibility JavaVersion.VERSION_1_8 
                 targetCompatibility JavaVersion.VERSION_1_8 
         } 
         ...... 
 } 
 dependencies { 
         implementation 'com.geospark.android:geospark:2.0.0' 
 }

//In onCreate method of your Application class include the code below.
public void onCreate() {
    super.onCreate();
    GeoSpark.initialize(this, "PUBLISH_KEY");
    ...
}    

GeoSpark.createUser(this,"User Description", new GeoSparkCallBack() {
       @Override
       public void onSuccess(GeoSparkUser geoSparkUser) {
                   geoSparkUser.getUserId();
       }
       @Override
       public void onFailure(GeoSparkError geoSparkError) {
                   geoSparkError.getErrorCode();
                   geoSparkError.getErrorMessage();
       }
});

//To enable location, call the requestLocationPermissions and 
//requestLocationServices method.
if(!GeoSpark.checkLocationPermission(this)) {
  	GeoSpark.requestLocationPermission(this);
} else if (!GeoSpark.checkLocationServices(this)) {
  	GeoSpark.requestLocationServices(this);
} else{
  	//Call this method to start tracking the location.  
  	GeoSpark.startTracking(this);
}