The most common advanced composer Wordpress plugin we have used is called Visual Composer by Atlassian. It is also included with many template files.
You can access full documentation for Visual Composer from - https://wpbakery.atlassian.net/wiki/display/VC/Visual+Composer+Pagebuilder+for+WordPress
If you run updates to your theme or core Wordpress files you may find that your Visual Composer will stop loading correctly. If this happens you will also need to update your Visual Composer software or revert to using the included Wordpress composer. To purchase an update to Visual Composer visit http://go.themeforest.net/visual-composer/