Rated 5 out of 5 stars

Thanks i disabled instant search as i hate that feature anyway and its buggy, Nothing to do with your addon, So this addon works great!

Rated 4 out of 5 stars

Thanks but still doesn't seem to work on google search or a few other sites.

This review is for a previous version of the add-on (1.0.1.3). 

Only form submissions can be directed to new tabs or windows; this is a fundamental limitation that no extension (or even a proper in-browser implementation of this feature) could ever do anything about. In the case of Google, their instant search is not a form submission, so there is nothing to capture and redirect. If you disable instant search, TabSubmit will work with on Google.