Apple can allow you to check parts of iOS third-party apps without installing them on your iPhone by scanning a QR code based on code from an early iOS 14 build reviewed by 9to5Mac. The feature apparently forms part of a new API named "Clips" in iOS 14.
According to 9to5Mac, the Clips API "allows developers to offer interactive and dynamic content from their apps even if you haven’t installed them." Apparently a card will appear when you scan a QR code that lets you connect with the sections of the app. The card can also allow users to opt to download a complete version of the app from the App Store, or open the interactive experience in that app if you already have the app that the QR code is previewing.
According to the code viewed by 9to5Mac, Apple could check the latest app previews with OpenTable, Yelp, DoorDash, Sony's PS4 Second Screen app and YouTube.
This latest functionality sounds much like the Android Slices feature that surfaces parts of an app in search results and in Google Assistant, or the Instant Apps from Android that loads a tiny version of an app when you tap a link. Nonetheless, 9to5Mac says the code it checked addresses only Clips API integration with QR codes, and it's uncertain if Apple plans to incorporate the new functionality with Spotlight, Siri or other parts of iOS.
It seems that the supposed iOS 14 feature will function differently, either serving as a way for users to test out some features of the app without actually installing it, or as a way for third party developers to provide certain features without asking a user to access their platforms.
Also, reportedly, iOS 14 will include iCloud Keychain updates, a new home screen list view, a new fitness app and more. Apple is expected to launch iOS 14 and the other 2020 software updates at this year's WWDC, which is attributable to the COVID-19 pandemic being housed in a new virtual environment.