The U.S. Patent and Trademark Office (USPTO) on Thursday published an Apple (AAPL) patent application showing the digital crown attached to iOS-based devices like the iPhone and iPad, according to Patently Apple, which earlier discovered the application. The patent says that the feature, which Apple refers to as a “rotary input” in the application, could be used to turn on and lock the screen, take pictures, and perform a wide range of other actions.

Apple Watch launched last year with a digital crown providing a host of features, including the ability to access the software’s home screen, zoom in on items, scroll through apps, and more. The feature looks similar to a dial one would find on a standard watch enabling them to change the time. Apple incorporated the concept into its smartwatch to make interacting with its watchOS mobile operating system a bit easier.

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Since the iPhone launched in 2007, Apple has relied upon touch inputs to control software across the iPhone and iPad. However, that changed a bit last year with the iPad Pro’s launch when Apple allowed users to interact with the software via the company’s Apple Pencil, a stylus-like accessory letting users write on the screen and perform other functions, like tap on icons and scroll through content.

Exactly why Apple would consider adding a digital crown to the iPhone or iPad is unknown. The feature, after all, makes sense on an Apple Watch, but it might not have much use on a smartphone or tablet where moving around software is as simple as using one’s fingers. However, in its patent application, Apple suggests that it could launch a device with no bezel and nothing but touchable glass, and the “rotary input” could be a useful way to move around the software without fearing touching something on the screen.

Of course, a patent application doesn’t necessarily mean that Apple will launch the feature, and the company has given no indication that the digital crown will come with the iPhone and iPad. Like many other companies, Apple files patents for all kinds of technologies and often times, those technologies don’t make their way to devices. It’s possible the same could happen with an iPhone- or iPad-based digital crown.

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Still, it would be an interesting confluence of Apple Watch and the iPad (or iPhone).