Here are a couple tutorials explaining some different features of SimpleD. Send me a note if you want a specific area covered.
You might have noticed there are two sets of color selector chips. What's up with that? This video explains the difference.
Here's a quick intro to creating custom SVG shapes for SimpleD. I used Adobe Illustrator and Adobe Shape in this process, but you could use any drawing tool that creates SVGs.
You want a connector. So use Alt to get one. Or Alt-Shift if you're getting fancy.