Simple and useful Rated 5 out of 5 stars

Nice one, but please open duplicate tab in foreground not in background mode.
Thank you.

This review is for a previous version of the add-on (0.0.2.1m). 

There is a config.
Open about:config and change extensions.duplicateintabcontext.loadInBackground to 0.
All duplicated tab will open in foreground.