When you're on a reddit page, use the share sheet to run this workflow and it will put this in front of the url, redirecting you into the app at the same page you were looking at in Safari.
My most common use case for this would be if I'm researching something and I end up on Reddit (if I know I'm going to Reddit I just open Narwhal to begin with). I don't like using the official Reddit app so this simple extension is well worth it for me.
With Workflow, some of the most basic ones can turn out to be the most useful. This one is only 2 actions yet it very valuable to me. I think something important to remember is not every Workflow you make has to be super complicated and filled with dozens of actions to be worth a spot in your collection.
You can get the workflow here.