title: Check for installed apps on iOS 9 and 10
body: <p>I am trying to check if a user has installed a couple of apps. I need it to work on ios9 and ios 10.
      I am testing on ios9 first and the <code>schemeAvailable</code> func is returning true even though the app passed
      is not installed on the device.</p>
  
  <pre><code>func schemeAvailable(scheme: String) -&gt; Bool {
     if let url = URL(string: scheme) {
         return UIApplication.shared.canOpenURL(url)
     }
     return false
  }
  </code></pre>
  
  <p>I have added the following to my info.plist i.e. the apps I will check are installed:</p>
  
  <pre><code>&lt;key&gt;LSApplicationQueriesSchemes&lt;/key&gt;
  &lt;array&gt;
  &lt;string&gt;app1&lt;/string&gt;
  &lt;string&gt;app2&lt;/string&gt;
  &lt;/array&gt;
  </code></pre>
  
  <p>and in my project's info tab, I have added 2 url types and inserted the identifier and url scheme for each.</p>