Add-ons for Calculator Builder | CalcHub

Hello, I installed Calculator Builder | CalcHub and took it for a spin. It seems to be suitable for my use case. I’m planning to purchase some of your add-ons. However I’m a little confused as to where I should purchase the add-ons from, as there are 3 different sites where they are available.

https://wpcalc.com/ —-> this site seems to have the most complete listing of add-ons (please correct me if I’m wrong)

https://wow-estore.com/

https://calchub.xyz