If you are lazy like me, you'll love this addon :) I created this for myself to avoid the hassle that can come with inviting people to your guild (especially BNet friends with weird letters in their names)
How this addon works: This addon listens to your whispers; and if it sees a trigger text ("ginv" for example) it'll send out an invite to that character Due to restrictions, for guild invites you'll have to click on a popup box to actually invite the player to your guild
Currently, there are 5 default 'triggers': "ginv", "guildinv", "ginvite" for guild invites "inv", "invite" for group/raid invites
Most of the functionality can be customized through settings (type "/iow")
Classic support
I do not actively play classic, so there won't be extensive testing there; but for now it seems to work fine. If you find any issues, feel free to report them, but please mention which game version you're playing :)