diff --git a/.gitmodules b/.gitmodules
index b87baff..e6aad27 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,6 +1,6 @@
 [submodule "includes/iworks/rate"]
 	path = includes/iworks/rate
-	url = git@bitbucket.org:iworks-pl/iworks-rate.git
+	url = git@github.com:iworks/iworks-rate.git
 [submodule "includes/iworks/options"]
 	path = includes/iworks/options
 	url = git@github.com:iworks/wordpress-options-class.git
diff --git a/includes/iworks/class-iworks-pwa.php b/includes/iworks/class-iworks-pwa.php
index 84fc272..39e9577 100644
--- a/includes/iworks/class-iworks-pwa.php
+++ b/includes/iworks/class-iworks-pwa.php
@@ -47,6 +47,13 @@ abstract class iWorks_PWA {
 	 */
 	protected $settings_cache_option_name = 'ipwac_';
 
+	/**
+	 * option to check meta viewport
+	 *
+	 * @since 1.5.1
+	 */
+	protected $option_name_check_meta_viewport = 'iworks_pwa_meta_viewport';
+
 	protected function __construct() {
 		$file        = dirname( dirname( __FILE__ ) );
 		$this->url   = rtrim( plugin_dir_url( $file ), '/' );
diff --git a/includes/iworks/pwa/class-iworks-pwa-administrator.php b/includes/iworks/pwa/class-iworks-pwa-administrator.php
index 58a2512..2903460 100644
--- a/includes/iworks/pwa/class-iworks-pwa-administrator.php
+++ b/includes/iworks/pwa/class-iworks-pwa-administrator.php
@@ -73,6 +73,13 @@ public function __construct() {
 		add_action( 'update_option_site_icon', array( $this, 'clear_cache' ) );
 		add_action( 'update_option_siteurl', array( $this, 'clear_cache' ) );
 		add_action( 'update_option_stylesheet', array( $this, 'clear_cache' ) );
+		/**
+		 * check meta viewport actions
+		 *
+		 * @since 1.5.1
+		 */
+		add_action( 'shutdown', array( $this, 'meta_viewport_check' ) );
+		add_action( 'after_switch_theme', array( $this, 'meta_viewport_delete' ) );
 	}
 
 	public function filter_add_debug_urls_to_config( $options ) {
@@ -271,5 +278,57 @@ public function close_pointer() {
 		$dismissed_pointers[] = $this->pointer_name;
 		update_user_meta( get_current_user_id(), 'dismissed_wp_pointers', implode( ',', $dismissed_pointers ) );
 	}
+
+	/**
+	 * check meta viewport - on shutdown
+	 *
+	 * @since 1.5.1
+	 */
+	public function meta_viewport_check() {
+		if ( ! is_admin() ) {
+			return;
+		}
+		$value = get_option( $this->option_name_check_meta_viewport );
+		if ( ! empty( $value ) ) {
+			return;
+		}
+		if ( isset( $_GET[ $this->option_name_check_meta_viewport ] ) ) {
+			return;
+		}
+		$url      = add_query_arg(
+			array(
+				$this->option_name_check_meta_viewport => 'checking',
+				'timestamp'                            => time(),
+			),
+			home_url()
+		);
+		$response = wp_remote_get( $url, array( 'sslverify' => false ) );
+		if ( is_wp_error( $response ) ) {
+			return;
+		}
+		$html = wp_remote_retrieve_body( $response );
+		if ( preg_match_all( '/<meta[^>]+/', $html, $matches ) ) {
+			foreach ( $matches[0] as $one ) {
+				if (
+					preg_match( '/name=["\']viewport["\']/', $one )
+					&& preg_match( '/initial-scale/', $one )
+				) {
+					update_option( $this->option_name_check_meta_viewport, 'valid' );
+					return;
+				}
+			}
+		}
+		update_option( $this->option_name_check_meta_viewport, 'missing' );
+	}
+
+	/**
+	 * delete meta viewport - on after_switch_theme
+	 *
+	 * @since 1.5.1
+	 */
+	public function meta_viewport_delete() {
+		delete_option( $this->option_name_check_meta_viewport );
+	}
+
 }
 
diff --git a/includes/iworks/pwa/class-iworks-pwa-frontend.php b/includes/iworks/pwa/class-iworks-pwa-frontend.php
index 8c5826a..c85d08a 100644
--- a/includes/iworks/pwa/class-iworks-pwa-frontend.php
+++ b/includes/iworks/pwa/class-iworks-pwa-frontend.php
@@ -29,7 +29,7 @@ public function __construct() {
 	}
 
 	private function add( $action ) {
-			add_action( $action, array( $this, 'add_to_home_screen' ) );
+		add_action( $action, array( $this, 'add_to_home_screen' ) );
 		add_action( 'wp_enqueue_scripts', array( $this, 'register_styles' ), 0 );
 		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_styles' ) );
 	}
@@ -74,6 +74,20 @@ private function before() {
 	 */
 	public function html_head() {
 		$this->before();
+		/**
+		 * add meta viewport - on wp_head
+		 *
+		 * @since 1.5.1
+		 */
+		if ( 'missing' === get_option( $this->option_name_check_meta_viewport ) ) {
+			printf(
+				'<meta name="viewport" content="width=device-width, initial-scale=1" />%s',
+				$this->eol
+			);
+		}
+		/**
+		 * manifest.json
+		 */
 		printf(
 			'<link rel="manifest" href="%s" />%s',
 			wp_make_link_relative( home_url( 'manifest.json' ) ),
@@ -84,6 +98,9 @@ public function html_head() {
 			wp_make_link_relative( home_url( 'manifest.json' ) ),
 			$this->eol
 		);
+		/**
+		 * theme color
+		 */
 		printf(
 			'<meta name="theme-color" content="%s" />%s',
 			$this->configuration['theme_color'],
diff --git a/package.json b/package.json
index 73fd9b6..435aa9c 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
     "title": "PWA — easy way to Progressive Web App",
     "tagline": "Your easy way to Progressive Web Application.",
     "description": "Progressive Web Apps (PWA) is a technology that combines the best of mobile web and the best of mobile apps to create a superior mobile web experience. They are installed on the phone like a normal app (web app) and can be accessed from the home screen.",
-    "version": "1.5.0",
+    "version": "1.5.1",
     "homepage": "http://iworks.pl/en/plugins/iworks-pwa/",
     "author": [
         {
diff --git a/readme.txt b/readme.txt
index d10c6ad..96fe53a 100644
--- a/readme.txt
+++ b/readme.txt
@@ -94,6 +94,10 @@ A2HS is supported in all mobile browsers, except iOS webview. It's also supporte
 
 == Changelog ==
 
+= 1.5.1 (2022-09-10) =
+* Added checking for a tag meta with the "viewport" value. Add it if it is missing. Props for [Bert](https://wordpress.org/support/users/bertluch/)
+* Changed [iWorks Rate Module](https://github.com/iworks/iworks-rate) repository to GitHub.
+
 = 1.5.0 (2022-08-03) =
 * Added `Add to Home screen` button to show browser prompt to install "app". Check [Browser compatibility](https://developer.mozilla.org/en-US/docs/Web/API/BeforeInstallPromptEvent#browser_compatibility).
 * Added google campaign track to "start_url" in `manifest.json` file.