I have been playing with the program and made my site into an APP.
But if a click/push on the link what is a link to a pdf file I get a spinning circle that will not go away.
You need to debug your app to check console error and get to know the exact issue:
Ask the website developer to use the download attribute in the link to PDF files.
<a download="filename.pdf" href="pathurl/filename.pdf">LINK</a>
<a download="book1.pdf" href="https://mysite.me/encryptedpath/keyasdasdasd?redirect">Download</a>
It may not work for customers with Android devices older than version 5.1, this is due to the WebView version.
If that doesn't work, the webmaster will need to modify the htaccess file to force direct download of files in specific formats: