Added about activity.

.idea/misc.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">

src/main/AndroidManifest.xml

@@ -84,6 +84,7 @@ limitations under the License.
         android:theme="@style/ThemeCustom"
         tools:replace="android:label">
         <!-- Activities -->
+        <activity android:name="de.dennisguse.opentracks.AboutActivity" />
         <activity
             android:name="de.dennisguse.opentracks.AggregatedStatsActivity"
             android:label="@string/menu_aggregated_statistics" />

src/main/java/de/dennisguse/opentracks/AboutActivity.java

@@ -0,0 +1,37 @@
+package de.dennisguse.opentracks;
+
+import android.os.Bundle;
+import android.view.Menu;
+import android.widget.TextView;
+
+import androidx.annotation.Nullable;
+
+import de.dennisguse.opentracks.util.SystemUtils;
+
+public class AboutActivity extends AbstractActivity {
+
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        setTitle(getString(R.string.about_preference_title));
+
+        TextView textDescription = findViewById(R.id.about_text_description);
+        textDescription.setText(getString(R.string.about_description));
+
+        TextView textVersion = findViewById(R.id.about_text_version);
+        textVersion.setText(getString(R.string.about_version, SystemUtils.getAppVersion(this)));
+
+        TextView textURL = findViewById(R.id.about_app_url);
+        textURL.setText(getString(R.string.about_url, getString(R.string.app_web_url)));
+    }
+
+    protected int getLayoutResId() {
+        return R.layout.about;
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        return false;
+    }
+}

src/main/java/de/dennisguse/opentracks/util/IntentUtils.java

@@ -36,8 +36,6 @@ import java.io.File;
  */
 public class IntentUtils {
 
-    public static final String TEXT_PLAIN_TYPE = "text/plain";
-
     private IntentUtils() {
     }
 

src/main/res/layout/about.xml

@@ -0,0 +1,76 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+
+    <ImageView
+        android:id="@+id/imageView"
+        android:layout_width="match_parent"
+        android:layout_height="239dp"
+        android:contentDescription="@string/image_my_tracks_logo"
+        android:scaleType="fitCenter"
+        android:src="@drawable/ic_logo" />
+
+    <TextView
+        style="@style/TextLarge"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:text="@string/app_name"
+        android:textSize="24sp" />
+
+    <View style="@style/StatsHorizontalLine" />
+
+    <TextView
+        android:id="@+id/about_text_description"
+        style="@style/TextMedium"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:padding="12dp" />
+
+    <View style="@style/StatsHorizontalLine" />
+
+    <TextView
+        android:id="@+id/about_text_version"
+        style="@style/TextSmall"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:padding="6dp" />
+
+    <TextView
+        android:id="@+id/about_app_url"
+        style="@style/TextSmall"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:autoLink="web"
+        android:gravity="center"
+        android:padding="6dp" />
+
+    <TextView
+        style="@style/TextSmall"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:autoLink="web"
+        android:gravity="center"
+        android:padding="6dp"
+        android:text="@string/about_history" />
+
+    <View style="@style/StatsHorizontalLine" />
+
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:padding="12dp"
+        android:text="@string/about_libraries" />
+
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:text="@string/third_party_libraries" />
+
+</LinearLayout>

src/main/res/values/do_not_translate.xml

@@ -14,12 +14,13 @@ See the License for the specific language governing permissions and
 limitations under the License.
 -->
 <resources>
-    <!-- DO NOT TRANSLATE ANY STRINGS IN THIS FILE. -->
+    <string name="app_web_url" translatable="false">https://github.com/dennisguse/opentracks</string>
     <string name="chart_x_axis_distance" translatable="false">DISTANCE</string>
     <string name="chart_x_axis_time" translatable="false">TIME</string>
+    <!-- List here all used libraries (will be shown in the about activity -->
+    <string name="third_party_libraries" translatable="false"><a href="https://developer.android.com/topic/libraries/support-library/">Google\'s androidX support</a> (Apache License, Version 2.0)</string>
     <string name="marker_statistics_icon_url" translatable="false">http://maps.google.com/mapfiles/ms/micons/ylw-pushpin.png</string>
     <string name="marker_waypoint_icon_url" translatable="false">http://maps.google.com/mapfiles/ms/micons/blue-pushpin.png</string>
-    <string name="app_web_url" translatable="false">TODO</string>
     <string name="permission_notification_value" translatable="false">de.dennisguse.opentracks.MYTRACKS_NOTIFICATIONS</string>
     <string name="sensor_type_value_none" translatable="false">NONE</string>
     <string name="sensor_unit_beats_per_minute" translatable="false">BPM</string>

src/main/res/values/strings.xml

@@ -15,7 +15,27 @@ limitations under the License.
 -->
 <resources>
 
-    <!-- Activity Type -->
+  <string name="about_preference_title" translate_description="In the about activity, the title.">
+    About OpenTracks
+  </string>
+  <string name="about_description" translate_description="In the about activity, the description of the app.">
+    <i>OpenTracks</i> is a sport tracking application that completely respects your privacy.
+  </string>
+  <string name="about_url" translate_description="In the about activity, the URL to the source code repository.">
+    Project web page: <a href="%1$s">%1$s</a>
+  </string>
+  <string name="about_version" translate_description="In the about activity, the version of the source code (i.e., Android's versionName).">
+    Version: %1$s
+  </string>
+  <string name="about_history" translatate_description="In the about activity, the relationship with MyTracks.">
+    OpenTracks is a fork of <a href="https://code.google.com/archive/p/mytracks/"><i>Google\'s MyTracks</i></a> (discontinued in 2016).
+  </string>
+
+  <string name="about_libraries" translatate_description="In the about activity, the header of the 3rd party libraries.">
+    Libraries
+  </string>
+
+  <!-- Activity Type -->
     <string name="activity_type_airplane" translation_description="When entering an 'Activity type', in the auto-complete text box, the
       completion suggestion for airplane.">
     airplane

src/main/res/xml/settings.xml

@@ -35,4 +35,10 @@ limitations under the License.
         android:key="@string/settings_advanced_key"
         android:persistent="false"
         android:title="@string/settings_advanced" />
+    <Preference
+        android:title="@string/about_preference_title">
+        <intent
+            android:targetPackage="de.dennisguse.opentracks"
+            android:targetClass="de.dennisguse.opentracks.AboutActivity" />
+    </Preference>
 </PreferenceScreen>