Document readers?

I need the ability to view documents like .docx and .pdf either within a Space app or invoked into some external iOS app, while offline.

I am storing the documents in base64 in the space SecureFiles store, which was fairly easy to setup and works quite well with images so far. However, I have no idea how to open a docx or pdf in the same manner.

I tried window.open("data:application/pdf;base64,...") to open a browser window but in Space it always results in replacing the app in the same window. I can get back to the app with the back arrow but it's clearly not a useful solution.

I tried the Ext.ux.panel.PDF extension but it doesn't work, it won't accept binary or string data and only works for pdfs anyways.

I read up on Invoke but can't seem to find any info about invoking a document reader on the device. Does such an invoke command exist? If not, any helpful suggestions would be greatly appreciated. Thank you!