AndroidManifest.xml

<receiver
  android:name=".TodayListWidgetProvider"
  android:exported="true"
  android:label="Today"
  >
  <intent-filter>
    <!-- Only broadcast that you must explicitly declare. The AppWidgetManager automatically sends all other App Widget broadcasts to the AppWidgetProvider as necessary. -->
    <action android:name="android.appwidget.action.APPWIDGET_UPDATE"/>
  </intent-filter>
  <meta-data
    android:name="android.appwidget.provider"
    android:resource="@xml/today_list_app_widget_info"
    />
</receiver>

<service
  android:name=".TopTodoListWidgetRemoteViewsService"
  android:exported="true"
  android:permission="android.permission.BIND_REMOTEVIEWS"
  />

today_list_app_widget_info.xml

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:initialLayout="@layout/today_list_large_widget"
  android:minWidth="@dimen/today_widget_width"
  android:minHeight="@dimen/today_widget_height"
  android:previewImage="@drawable/today_widget_preview"
  android:resizeMode="horizontal|vertical"
  android:targetCellWidth="2"
  android:targetCellHeight="1"
  android:updatePeriodMillis="86400000"
  android:widgetCategory="home_screen"
  >
  <!-- update every 1 day -->

  <!--
  86400000/1000/60/60/24
  = 1 day
  -->

  <!--
  Widget Size
  ((Number of columns / rows) * 74) - 2
  -->

  <!--
  android:previewImage="@drawable/widget_preview"
  -->

</appwidget-provider>