Add iOS app link

Author: bqqbarbhg

app/views/home/index.html.erb

@@ -16,6 +16,7 @@
     <% end %>
 
     <h4><%= link_to(t('.app.android'), 'https://play.google.com/store/apps/details?id=fi.aalto.legroup.achso') %></h4>
+    <h4><%= link_to(t('.app.ios'), 'https://itunes.apple.com/us/app/ach-so!/id1078968376') %></h4>
 
   </div>