Sidecar is a new feature introduced by Apple in macOS Catalina, and its purpose pretty much comes down to enabling an iPad to play the role of a secondary screen for Mac.
The bad news is that Sidecar doesn’t support all Macs and iPads, so getting this feature on older models, even if they run macOS Catalina, wasn’t possible.
Until recently, that is, as a new software solution called Free Sidecar enables this functionality on all previously-unsupported iPads and Macs updated to macOS Catalina.
Because Apple just turns to a typical blacklist approach to prevent older devices from enabling Sidecar, this app serves as a UI for editing the SidecarCore and technically removing the block.
Apple could block it
The app runs in a sandbox and doesn’t even require root access, but what’s worth knowing is that the wireless mode may not work on all older devices. However, the entire process doesn’t take more than a few minutes, with two restarts required to make the changes.
“This app works on all versions of iPadOS and macOS Catalina, including upcoming releases (assuming Apple doesn’t change how they blacklist devices—in which case this app will be a no-op),” the developer of Free Sidecar explains on the GitHub page.
As the developer themselves admitted, Apple could very block this application from working in a future update, albeit this comes down to the company finding a different way to block older iPads and Macs from using Sidecar. If nothing changes and Apple sticks with the existing blacklist system, there’s a good chance Sidecar can still be enabled with this app.
You can find all devices supported by Free Sidecar (and not supported by Apple’s Sidebar) in the box below and have a look on the linked GitHub page for full instructions on how to use this app.