Below there are some comments that amount to this extension being "inflexible" because it won't work on a global basis but only on individual tabs. The extension is called "Rename Tab Title" and that is exactly what it does. If it renamed every tab from a particular site to exactly the same tab title it would be of no value to me and would indeed be "inflexible". The whole point, surely, is to pinpoint a specific url by a chosen name.
It works just fine (does what it says on tin).