This is the only available plugin I think for the latest version of joomla to show browser update warning.
There is just a small issue that the css not better work with older browser like ie6 to show warning, as we know this plugin work is to warn people that they are using old browser so the warning must look better and at place in older browsers.
And I haven't found the file to do modification in css or main file of the plugin? where it get installed I am not able to see it in plugin system folder?
Overall its working fine and able to show all the download options and continue if people want.