As a leak had previously suggested, iPadOS 13 brings USB mouse support to the iPad. Apple has added it to the OS as an AssistiveTouch feature.
This means that like other AssistiveTouch features, connecting a USB mouse to your iPad running iPadOS 13 will show a black touch target simulating a finger touch.
This means as you move the mouse around, it will scroll through lists and you can click on an item to simulate a tap. As developer Steve Troughton-Smith notes, the feature even works with Apple’s own Magic Mouse.
— Steve Troughton-Smith (@stroughtonsmith) June 3, 2019
The feature works with both wired and wireless USB mouse. If you own a wireless mouse, you just need to plug in their USB receiver to your iPad or iPad Pro running iPadOS 13.
Apart from USB mouse support, iPadOS also brings native support for external USB drives and cameras to the iPad. The enhanced Files app in the OS can natively read pen drives, cameras, and external hard disks, and you can even import photos directly to Lightroom or any other photo-editing app of your choice from external storage. The new Files app also has support for SMB and iCloud Shared folders which makes file management easier on an iPad.
The move to add support for USB mouse and external storage means that Apple could potentially add support for more USB devices to iPadOS in the future.