So if you're near a Starbucks, the Starbucks app will appear on the lock screen for easy access. That way you can more easily pay for your coffee using the Starbucks app.
As MacRumors points out, it's unclear right now which apps will be supported. But it might not be limited to big companies or Apple-related apps.
A developer took to Twitter to show that a train app appeared when he got to his train station.
So I'm at the train station and #iOS8 shows me my most(?) use app! #nearby #app pic.twitter.com/kPLnYvr7xo
- Cyril Gabathuler (@gabac) June 3, 2014
So it seems that apps that actually need you to do something - pay or show a ticket - will be featured on the main screen. Apple mentions in its release notes that it uses Location Services to recommend relevant apps: "When Location Services is turned on, the device's current location is used to recommend relevant apps on the lock screen."
It also appears to be tied to the App Store. Apple will suggest apps for you to install, based on your proximity to a location, according to MacRumors.
This is yet another big change for Apple. It opens up all sorts of possibilities like app makers paying for placement on the lock screen, though we down that will happen.
It's also part of Apple's attempts to make app discovery better. There are now 1.2 million apps in the App Store, and it's hard for users to find the right app. This is another take on trying to solve that problem.