Inappbrowser opening internal pdfs, rendering very slowly iOS/iPad

Hopefully someone has experienced this same issue.

I have a number of PDFs in my App that I am opening and viewing with the inappbrowser plugin. It all works well except the PDFs are quite big and rendering takes a long time so I see blank pages for a while, waiting for the content to render.

Is there a way of implementing a spinner or something so that more of the document loads and the user doesn’t have to deal with laggy rendering?