Safari should start the download automatically. Click on the arrow icon at the top of this window and wait until the download is finished.
Click on the 2stitch-1.1.1.dmg to continue with the installation.
You should see a window like the one below after a short time. If this is not the case open your Downloads folder in Finder and double-click 2stitch-1.1.1.dmg.
Drag the 2stitch Organizer.app icon from the left onto the Application folder to install it:
2stitch Organizer is now installed. Open Finder and navigate to the Applications folder. Double click the 2stitch Organizer icon to start it.
macOS presents you with a warning that this application was downloaded from the internet from www.codeandweb.com — this is ok. (CodeAndWeb is our company and we store the downloads for 2stitch on the main page for simplicity). Simply click Open: