Add Safari/iOS versions of the logo

app/views/layouts/_head.html.haml

@@ -7,14 +7,25 @@
   %title= page_title
 
   = favicon_link_tag 'favicon.ico'
-  = stylesheet_link_tag    "application", :media => "all"
-  = stylesheet_link_tag    "print", :media => "print"
+
+  = stylesheet_link_tag "application", media: "all"
+  = stylesheet_link_tag "print",       media: "print"
+
   = javascript_include_tag "application"
+
   = csrf_meta_tags
+
   = include_gon
+
   %meta{name: 'viewport', content: 'width=device-width, initial-scale=1, maximum-scale=1'}
   %meta{name: 'theme-color', content: '#474D57'}
 
+  -# Apple Safari/iOS home screen icons
+  = favicon_link_tag 'touch-icon-iphone.png',        rel: 'apple-touch-icon'
+  = favicon_link_tag 'touch-icon-ipad.png',          rel: 'apple-touch-icon', sizes: '76x76'
+  = favicon_link_tag 'touch-icon-iphone-retina.png', rel: 'apple-touch-icon', sizes: '120x120'
+  = favicon_link_tag 'touch-icon-ipad-retina.png',   rel: 'apple-touch-icon', sizes: '152x152'
+
   = yield :meta_tags
 
   = render 'layouts/google_analytics' if extra_config.has_key?('google_analytics_id')