2. Debug ObjectsWordPress Plugin for debugging and learning with and at the application.
10. Simple-Media-Queries-DebuggingMedia Queries are going to establish, the pros and cons are not an issue here. "Debugging" is not easy and creating layouts can be quickly complex. This solution is an idea to know the viewport, since it shows in the upper area of the page. Via these values you can use it for different width.
13. wp-offlineUse WordPress without all online-checks. Deactivate autoupdate for core, plugins and themes
16. adminimizeAdminimize is a WordPress plugin that lets you hide 'unnecessary' items from the WordPress backend.