Pop is simply a convenient place for writing things down — that piece of paper you grab to write when you have an idea. It doesn't help you do anything smarter or more organized.
'Copy All' and 'Read' are the only features, to make it easy to use your words or read uninterrupted. Anything else seems to add a little more noise, a little less focus. Sometimes you don't need more features.
The little extra effort of having to Copy All and Paste your way out encourages quality and focus. If the words aren't worth a copy and paste, clear the page.
Further Info and Instructions for Pop
How Minimal Can a Minimalist App Get? Try Pop - The Next Web
Pop Is a Simple Notepad for Quickly Jotting Down and Vetting Notes | Lifehacker
Quarter-Life Enlightenment - A Place for Pop