Google’s Webmaster Tools made an addition of much functionality such improvements on features such a Sitemaps and Crawl errors, as well as the new User Administration feature. Webmaster Tool also updated the look and feel of its user interface to match Google’s new style.
Webmaster Tools regularly reviews each of its features with the thrust of seeing the features are still helpful in comparison to the maintenance and support they require. Due to Webmaster Tool’s latest round of spring-cleaning, they removed the Subscriber stats feature, the Create robots.txt tool and the Site performance feature.
What does a Subscriber stats do?
This feature reports the number of subscribers to a site’s RSS or Atom feeds; it is currently offered in Feedburner, another Google product which provides its own subscriber stats as well as other cool features exclusively geared for feeds of all types. Anyone looking forward to replace in Webmaster Tools should check out Feeburner.
Create robots.txt files
This feature offers a way to generate robots.txt files for the purpose of blocking specific parts of site from being crawled by Googlebot. Google’s Webmaster Tool removed this feature owing to its low usage. Many websites rarely require robots.txt file but users who need one can make one for themselves in text editors or alternatively make use of the many other tools available on the web for generating robots.txt files.
Site performance
Is a Webmaster Tools Labs tool that offers information about the average load time of your site’s pages, the feature was also detached owing to low usage. Webmaster Tools has many other site performance analysis tools available such as WebPage test and the YSlow browser plugin.
Source: https://googlewebmastercentral.blogspot.com/2012/04/webmaster-tools-spring-cleaning.html