Can you close apps with the Apple Pencil?

Another way to do this, IF you just want to use your Apple Pencil is to setup Accessibilty and bring out the Accessibility button on your iPad's screen and program the Accesibilty button for commonly used functions.

Go into the Settings app, Accessibility panel, in the right hand side column, tap the “Touch” panel under the “Physical and Motor category”.

Then tap Assistive Touch and then toggle ON Assistive Touch.

Then tap Customise Top Menu.

These let's you assign multiple functions to the Assistive Touch button that is atop your iPad's screen.

I have mine set/arranged for Home screen, Screen Shot, Siri, App Switcher, Dock, Control Center.

This way I have one button tap access to multiple basic iOS/iPadOS functions/features of iOS/iPadOS using either my finger OR Apple Pencil to tap onto and the button is positioned near the edge or top of the Dock, out of the way of most app menus.

Try this, see if you like thus.

I have been using the Accessibility button like this for years on all of my iPads for many years!

Best of Luck to You!

No, you cannot force-close an App using the Pencil. An App can only be force-closed from the App Switcher.

To summon the Task Switcher, it is necessary to you swipe upwards with your finger from below the active portion of the screen, to the middle of the screen - and pause briefly - before lifting your finger; App can then be closed by swiping the App thumbnail off the top of the screen. Alternatively, the Task Switcher can be summoned by a double-click of the Home button on iPads so equipped.

Once you bring up the iOS App Switcher, you CAN use the Apple Pencil to swipe apps up to quit them using the Apple Pencil.

If using your fingers, you can also use multiple fingers to quit multiple apps in the iOS App Switcher, as well.