vaniivan

This plugin warns you of server IP address changes, so you can take care of Search Engine Visibility settings. 
This can happen if you move your database between development, staging and production environments, or on the first deployment of your site. 
It’s bad to keep robots.txt on for production, but could also be bad if you leave the robots.txt off on staging or development, 
since the whole staging.example.com domain could be indexed by Search Engines.
<h3>External Services</h3>
This plugin makes use of the http://ipecho.net service for external IP address resolution. More info here: https://ipecho.net/developers.html

A3 Robots Warning

Warns you of server IP address changes, so you can take care of Search Engine Visibility settings.

citywanderer

Miina Sikk

Unblock CSS & JS for Googlebot plugin allows Googlebot to access the JavaScript and CSS files.
Google periodically sends to webmasters warnings that their JavaScript .js files and their CSS stylesheets are blocked – even when the webmasters have never explicitly done so. In fact, it is estimated that 85% of all users of Google webmaster tools have received such a warning.
Unblock CSS & JS for Googlebot solves this problem for you — and no configuration is needed. Just install and activate the plugin.
How does it work? It just adds in three lines to your robots.txt file to ensure the Google spider can get through.
You don’t want it anymore? Just uninstall and the added lines will be removed.
For more information and support, check out: http://www.wpsos.io/wordpress-plugin-unblock-css-js-for-googlebot/

Unblock CSS & JS for Googlebot

Modifies robots.txt to allow Googlebot access JS and CSS files.

A3 Robots Warning vs Unblock CSS & JS for Googlebot