Detect if browser has RSS/News Aggregator installed

The following code will read the plugins of a browser and display what plugins there are:

<div id="pluginDisplay"></div>
<script type="text/javascript">
    var x = navigator.plugins, y = x.length, z = "Plugins: <br />";
    for(j = 0; j < y; j++){
          z += navigator.plugins.name + "<br />";
          }
    document.getElementById('pluginDisplay').innerHTML = z;
</script>

If there is a way to do the same for extensions, that is what I am trying to find.  Is anyone aware of a way to do this?

V/r,

^ _ ^

There is an api that will detect native installed apps, if I remember correctly look for info on the js function -

getInstalledRelatedApps()

You will have to check on browser support, but I dont think IE has support

It will obviously not work on mobile devices, so you will have to ask the user to open in an installed app, but I think something changed in iOS 10 and a method to transfer to the app was I think introduced, (not certain, sorry).