If you want to publish immediately all scheduled posts in WordPress–you need to use Phpmyadmin.  If your host has Cpanel, you can find Phpmyadmin in there, but you need to be careful here because you can screw things up if you don’t know what your doing.  Once you locate the database of your site on the left links menu, just click on WP Posts section and once in there click on SQL in top center.

Paste this and Voila you will bulk publish all scheduled posts.  Easier than dealing with plugins.  I was unable to find any plugin that mass publishes all scheduled posts.   You can also substitute future for word Draft and that will do the same for all draft posts.

UPDATE wp_posts SET post_status = ‘publish’ WHERE post_status = ‘future’;

Phpmyadmin wordpress bulk publish scheduled posts