How can I make everything smaller on my Samsung Note 4?

I just bought a Note 4, which has a huge 1440p screen, and yet everything seems so big. For example, I can only fit four rows by four columns of icons. I would like to take advantage of the 1440p screen to fit more icons. Also, my apps are all huge as well. For example, my twitter app can only show two or three tweets at a time! How can I make everything smaller and take advantage of that high resolution screen?

I should also note that I'm using the Google Now launcher as my default home screen.

Thanks in advance for your wisdom!