Welcome to XF2 Addons. You can buy my Premium membership for $35 per year, and this gives you access to download any or ALL of the 300 add-ons that I have developed for Xenforo 2.x. In addition, Premium members will get technical support. Once the Premium membership has expired you can continue to use the installed addons on your forum as long as you like.
People share links to point people at things they have found that other readers might find helpful. But these links often go out of date or even worse, the domain expires and gets taken over by something completely unrelated. This addon is great as it enables you to link to the content *as it was* when the person originally shared it.