Allow License Transferslets you enable or disable users unbinding their key or subscription and giving it to someone else. (Ex. trades or sales for your product)
Require Purchaser to be in Discordon.
Require Ownership of Other Productallows you to require people to own product x to be able to purchase product y.
Require to be following on Twitteron and your users will be prompted with Twitter oAuth to sign in and check to see if the user is following and automatically follow your account if they are not.