If you've bought the iPad Pro 2018 and the Apple Pencil (2nd generation), you may want to enjoy the double-tap feature offered by the latter. You can either set the double-tap feature to switch between pen and eraser or to create a custom color.
To do so
- Open your iPad's Settings.
- In the list of settings, tap Apple Pencil.
- Select Switch Between Current Tool and Eraser or Show Color Palette.
You can now use your Apple Pencil's double-tap feature in Nebo.