diff --git a/app/build.gradle b/app/build.gradle
index 319fe31..9237e4e 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -36,11 +36,11 @@ android {
 }
 
 dependencies {
-    implementation 'com.google.android.material:material:1.1.0-alpha10'
+    implementation 'com.google.android.material:material:1.2.0-alpha04'
     implementation 'androidx.preference:preference:1.1.0'
-    testImplementation 'junit:junit:4.12'
+    testImplementation 'junit:junit:4.13'
     testImplementation 'org.robolectric:robolectric:4.1'
-    googleImplementation 'com.google.firebase:firebase-core:17.2.0'
+    googleImplementation 'com.google.firebase:firebase-core:17.2.2'
     googleImplementation 'com.crashlytics.sdk.android:crashlytics:2.10.1'
     googleImplementation 'com.google.android.gms:play-services-location:17.0.0'
 }
diff --git a/app/src/main/java/org/traccar/client/MainFragment.java b/app/src/main/java/org/traccar/client/MainFragment.java
index 909a2cf..a96ce0f 100644
--- a/app/src/main/java/org/traccar/client/MainFragment.java
+++ b/app/src/main/java/org/traccar/client/MainFragment.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2019 Anton Tananaev (anton@traccar.org)
+ * Copyright 2012 - 2020 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -60,6 +60,7 @@ public class MainFragment extends PreferenceFragmentCompat implements OnSharedPr
     public static final String KEY_ANGLE = "angle";
     public static final String KEY_ACCURACY = "accuracy";
     public static final String KEY_STATUS = "status";
+    public static final String KEY_BUFFER = "buffer";
 
     private static final int PERMISSIONS_REQUEST_LOCATION = 2;
 
@@ -169,6 +170,7 @@ public class MainFragment extends PreferenceFragmentCompat implements OnSharedPr
         findPreference(KEY_DISTANCE).setEnabled(enabled);
         findPreference(KEY_ANGLE).setEnabled(enabled);
         findPreference(KEY_ACCURACY).setEnabled(enabled);
+        findPreference(KEY_BUFFER).setEnabled(enabled);
     }
 
     @Override
diff --git a/app/src/main/java/org/traccar/client/TrackingController.java b/app/src/main/java/org/traccar/client/TrackingController.java
index 83c96ce..fd3a13b 100644
--- a/app/src/main/java/org/traccar/client/TrackingController.java
+++ b/app/src/main/java/org/traccar/client/TrackingController.java
@@ -35,6 +35,7 @@ public class TrackingController implements PositionProvider.PositionListener, Ne
     private SharedPreferences preferences;
 
     private String url;
+    private boolean buffer;
 
     private PositionProvider positionProvider;
     private DatabaseHelper databaseHelper;
@@ -50,6 +51,7 @@ public class TrackingController implements PositionProvider.PositionListener, Ne
         isOnline = networkManager.isOnline();
 
         url = preferences.getString(MainFragment.KEY_URL, context.getString(R.string.settings_url_default_value));
+        buffer = preferences.getBoolean(MainFragment.KEY_BUFFER, true);
     }
 
     public void start() {
@@ -78,7 +80,11 @@ public class TrackingController implements PositionProvider.PositionListener, Ne
     public void onPositionUpdate(Position position) {
         StatusActivity.addMessage(context.getString(R.string.status_location_update));
         if (position != null) {
-            write(position);
+            if (buffer) {
+                write(position);
+            } else {
+                send(position);
+            }
         }
     }
 
@@ -173,10 +179,14 @@ public class TrackingController implements PositionProvider.PositionListener, Ne
             @Override
             public void onComplete(boolean success) {
                 if (success) {
-                    delete(position);
+                    if (buffer) {
+                        delete(position);
+                    }
                 } else {
                     StatusActivity.addMessage(context.getString(R.string.status_send_fail));
-                    retry();
+                    if (buffer) {
+                        retry();
+                    }
                 }
             }
         });
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 4c8dc3e..180e398 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -20,6 +20,9 @@
   <string name="settings_status_on">Stop</string>
   <string name="settings_status_off_summary">Service stopped</string>
   <string name="settings_status_on_summary">Service running</string>
+  <string name="settings_buffer">Offline buffering</string>
+  <string name="settings_buffer_off_summary">Buffering off</string>
+  <string name="settings_buffer_on_summary">Buffering on</string>
   <string name="settings_accuracy_title">Location accuracy</string>
   <string name="settings_accuracy_summary">Desired location accuracy</string>
   <string name="settings_accuracy_high">High</string>
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
index c69f09a..0f0f2e6 100644
--- a/app/src/main/res/xml/preferences.xml
+++ b/app/src/main/res/xml/preferences.xml
@@ -31,22 +31,29 @@
     <EditTextPreference
         android:defaultValue="300"
         android:key="interval"
-        android:numeric="integer"
+        android:inputType="number"
         android:summary="@string/settings_interval_summary"
         android:title="@string/settings_interval_title" />
 
     <EditTextPreference
         android:defaultValue="0"
         android:key="distance"
-        android:numeric="integer"
+        android:inputType="number"
         android:summary="@string/settings_distance_summary"
         android:title="@string/settings_distance_title" />
 
     <EditTextPreference
         android:defaultValue="0"
         android:key="angle"
-        android:numeric="integer"
+        android:inputType="number"
         android:summary="@string/settings_angle_summary"
         android:title="@string/settings_angle_title" />
 
+    <CheckBoxPreference
+        android:defaultValue="true"
+        android:key="buffer"
+        android:summaryOff="@string/settings_buffer_off_summary"
+        android:summaryOn="@string/settings_buffer_on_summary"
+        android:title="@string/settings_buffer" />
+
 </PreferenceScreen>
diff --git a/build.gradle b/build.gradle
index e080ab9..d211b9d 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,8 +5,8 @@ buildscript {
         maven { url 'https://maven.fabric.io/public' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.2'
-        classpath 'com.google.gms:google-services:4.3.2'
+        classpath 'com.android.tools.build:gradle:3.5.3'
+        classpath 'com.google.gms:google-services:4.3.3'
         classpath 'io.fabric.tools:gradle:1.26.1'
     }
 }