Thanks to Alexander Danilenko, there is now a new debug tool coming with the Devel module. This new debug tool's name is Kint. They wanted to name it after Kant, but misspelled. (No, they didn't.) Kint's functionality is very much like Krumo's, except that it not only lists objects variables, but also their methods and constants. So far, Kint is only available in Drupal 8's devel package.
An update: Kint module is available for download form Drupal sandbox at https://www.drupal.org/sandbox/fat763/2155159 . There is a Drupal 7 version only there.