I bought a PS4 Slim and I want to buy Battlefield 1 on PSN, but my PS4 hasn't arrived yet. Can I buy the game without using a physical console?
From the app:
Once you get your PS4, just log into your account and go to your Purchased section of your Library (far right on the main menu) and Battlefield 1 should be there and available for download.
Another useful thing is that once you have a PS4 set up, you can remotely tell it to install games you've purchased from the app. It helps for those times your coworker convinces you to buy a game at work and you want to play as soon as you get home.