the name of the extension is not just 'Adblock Plus for Google Chrome' but Adblock Plus for Google Chrome™.
what is 'TM'?
[simple question] about 'TM' of its name
Re: [simple question] about 'TM' of its name
"™" stands for trademark, which indicates that Google have legal control over how their brand name "Google Chrome" is used. I suspect that Wladimir was required to add the symbol when he submitted the add-on to the Google Chrome extension gallery.