Tab Count is a Safari App Extension with a simple mission: help you see with a single glance how many tabs and windows you have open. It achieves this goal by adding a badge to the extensions toolbar icon.
Within the extensions popover, you may set thresholds as to how many tabs and/or windows ought to be open before a badge is applied.
Additionally you have buttons to close all tabs to the left or right of the currently active tab.
The extension will not have access to your browsing data and your privacy is thus protected.