You shouldn't see any slowdown. The code uses minimal resources - reads the table data, calls a webservice and injects the keyword volume and cpc numbers.
I can see the usefullness of this tool but it's not clear how to use it. I installed it but nothing changed (i.e. there's no button in the toolbar). I tried restarting Chrome hoping to see some changes, nothing. I went to the extensions settings page but all I see are checkboxes for different see screenshot: http://imgur.com/rOBCMmj
It would be extremely helpful to have even a basic tutorial page/link pop up after installation (you can add this hook in the manifest.json).
That's a good point. Will add a tutorial in the next version.
There is no setup to be done. Once the extension is enabled, you simply visit any supported website and the keyword metrics will show up automatically. Just google for a keyword and the keyword data should be seen under the search box. Visit Google Search Console or Analytics, and keyword columns automatically appear inside the table.
If you are having any issues with this, please do email me at support@keywordkeg.com and I'll be happy to figure out why its not working for you.
It would be extremely helpful to have even a basic tutorial page/link pop up after installation (you can add this hook in the manifest.json).