Heredis World 2017 for Mac, a cross-platform genealogy application is 50% off for three days (believe it ends Sunday, Nov. 26, 2017). Normally it’s $49.99, but right now it’s $24.99 on the Mac App Store.
Note: This discount applies to the macOS version, the Windows version, the Windows upgrade, and the Mac and Windows Bundles. The non-App Store versions and the Windows and bundle pricing are available at https://shop.heredis.com
If you want to try it out before buying it, you can download a free demo from Heredis.com.
The iOS and Android versions are free.