These are both tools for professional artists. Astropad lets you use your iPad as a second display for your Mac, with an emphasis on functioning as a tool for

These are both tools for professional artists. Astropad lets you use your iPad as a second display for your Mac, with an emphasis on functioning as a tool for artists. It used to support multiple iPad styluses but moved to only supporting the Apple Pencil. Sidecar lets you use your iOS13 iPad as a second display for your Catalina Mac, with an emphasis on functioning as a tool for artists. I have not used it but I am pretty sure it only supports the Apple Pencil. Both of these are sort of functioning as an alternative to buying an external monitor with pressure-sensitive stylus support, which is generally going to be more expensive than a tablet - Wacom's Cintiq line, for instance, runs from $700 for a 13-inch screen to $3300 for a 32-inch screen. They are also in competition with the growing power of tablet apps; there's a lot of former Photoshop painters who have switched to Procreate or the tablet version of Manga Studio to get their work done.