Download of SlideDraw 1.5.1 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software belongs to Design & Photo Tools. This free Mac app is a product of Workflow Network. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
SlideDraw is a macOS-based live presentation image annotation app designed to work with most touch screens. With macOS Catalina’s Sidecar feature, an iPad with the Apple Pencil is a perfect pairing. Also, via the Control Panel, on a 2nd screen, a user can assist in navigation and make slide changes while a prevention is live.
You may want to check out more Mac applications, such as Presentation Manager, Soundslides or Themes Box for Keynote, which might be similar to SlideDraw.