Apple has added a feature that allows developers to make new iOS 11 apps available for pre-order up to 90 days before release. So, if you want to download a new app you heard about, but you're afraid you'll forget about it by the time it's released (let's be honest, you probably will), you can now pre-order it.
The new feature will most likely affect gamers the most. In fact, Apple's iOS 11 App Store update features a new tab dedicated exclusively to games (no other category has its own tab). Certain games like the upcoming 2018 release of the augmented reality mobile game Harry Potter: Wizards Unite have tons of hype surrounding them before they're released, so being able to pre-order them will make things a lot easier.
Whether the app is free or paid, its product page will become available with the option to pre-order. Once the app is released, you'll be notified and the app will automatically download to your iPhone. If you paid for the app, you'll be charged before download.
Developers will be able to track how popular their upcoming app is before it's even released, and users will never miss a release date. A win-win for everyone!