How to make a dynamic radial menu?

So I’ve been looking around and can’t seem to find any answers or actually helpful links.
SO, I’m trying to make a radial menu similar to Prey’s radial favorites selector. I can’t seem to find any good tutorials for dynamic menu’s, only for preset sizes. I also found a marketplace item, but that seems to be deprecated and no longer updated, and there were no videos or posts doing breakdowns, so not at all helpful. The closest I found was the Dynamic Pie Menu, but I’d rather not buy anything, so I’d love to find some good tutorial or someone to explain how to make a dynamic pie menu. Help?

So… is your question “How do I make it” or “Where can I buy it made?”

“How do I make it”, sorry if I got things muddled in with my terrible wording, not my forte >_<

you have to show a radial menu on drag and on drop get drag location and find which option it was pointing to.
p.s its a hard thing to do .