Download and view PDF's inside AI2 app through webviewer

I'm trying to make an app that is able to download a PDF from a website and view it in the app as well.

But I'm having issues trying to download the PDF through the webviewer, any suggestions?

The standard webviewer is not connected to the android file system which makes downloading files difficult. There is a Custom Webview extension which provides this functionality:

I have downloaded the custom webview, but I can't find how to download PDF's from webpages.

Which blocks should I use?

Please read the link above, somewhere in there @ post #73 is how to do this.

If you are importing latest version (which you should) then an extension named DownloadHelper also gets imported.
After adding that extension to screen, head over to blocks and you can easily find the Download method block.
Just connect that to DownloadNeeded event and fill all method like shown in reply 73 of that topic.

Why not use the Web component, which can download file also?