I don’t text, but a lot of people do. I prefer to type messages from my computer, and I can “text” people from Thunderbird if I know their carrier. But I usually don’t, and it’s extra effort to Google their number, find their carrier, and then Google the domain based on carrier. I can’t find any add-on that does this on AMO. Can someone point me to one or build one?
For reference, this site shows carriers and the domains based on them.