As by default, you would have to either:
1) hit the drop-down to see the whole tab list; or otherwise
2) see that there are just more than 7-or-whatever-fits-in-screen.
tab-counter is a SeaMonkey add-on that counts the tabs in each window to let you know when there're too many - or just to know that you're a tab fan when the number gets over one hundred.
What's New in This Release: [ read full changelog ]
· Added context menu for the status bar item. It opens the preferences window.
· Update compatibility files.