Drupal's own form validation is way more flexible and accessible than the HTML5 validation your browser performs. Unfortunately, HTML5 validation is performed before Drupal validation, so Drupal validation never happens. This module disables browser validation in all your forms by adding the novalidate attribute to the form tag. Learn more why HTML5 validation is bad here: https://www.drupal.org/node/1797438
Hopefully, once this issue is resolved, this module isn't needed any more.