Certain graphics tablets, such as those from Wacom or XPPen, come with a limited-time free license (typically 3 to 24 months) as part of the purchase. Permanent Free Alternatives
While the desktop (Windows/macOS) and tablet (iPad/Android tablet) versions require payment after the trial, the works on a different model. clip studio paint for free
When a trial expires, the software doesn't stop working entirely. It enters a "Limited" mode. You can still open and draw on canvases. Certain graphics tablets, such as those from Wacom
If you want to test the waters before committing your wallet, here is what you need to know about the trial version: Certain graphics tablets