Startup Idea: PDF Viewer with 'Back' Feature for Research Purpose

Startup idea to develop a PDF viewer specifically for researchers, with a unique 'back' feature that enables them to easily navigate back to the beginning of their reading position. This feature aims to save time and improve their reading experience, as they often delve into reference links and struggle to return to their initial reading point.

I am a research scientist in a major US company.

One of the biggest pain point of my daily work lies on a software for viewing the pdf. I usually read documented pdf files on the web, which typically contains links to the references. The thing is, often I want to go back to the part of the document I was reading, but there is no shortcut that does this! So instead I am forced to scroll back to the position I was reading. This is annoying and tedious.

Therefore, a pdf viewer that has the "back" feature to the position that I was reading would be extremely helpful. I would imagine there must be a way to make such a program, but I am not aware of any. My colleagues and I agree that we will gladly pay for such a software provided it is sufficiently cheap, say $5.