Luke Gedeon

The default position for the menu in WordPress 2.7 is on the left, but since the scroll-bar is on the right, some people wanted the menu over there too. Plus a lot of blogs/websites have menus on the right so menu on the right seems to be a pretty popular option.
This plug-in moves WordPress admin menu to the right side of the screen.

Admin Menu on Right

Moves WordPress admin menu to the right side of the screen.

themifyme

Conditional Menus is a simple yet useful WordPress plugin by <a href="https://themify.me/" rel="nofollow ugc">Themify</a>, which allows you to swap the menus in the theme as per specific conditions. In short, you can have different menus in different posts, pages, categories, archive pages, etc. It works with any WordPress theme that uses the standard WordPress menu function.
<h3>How to use it</h3>
Once you activate the plugin, you will see the conditional menus on the Manage Locations tab located in your WP Admin > Appearance > Menus page.
1) To add conditional menu: click “Conditional Menu” and select a menu from the list (you can create these menus in the “Edit Menus” tab) 
 – You can remove the menu by selecting “Disable Menu” from the list. 
2) Click on “+ Conditions” to add conditions in the modal box (tick the checkboxes where you want the menu to appear) 
3) To remove the conditional menus, click on the “X” button
Visit https://themify.me/conditional-menus for more details.

Conditional Menus

This plugin enables you to set conditional menus per posts, pages, categories, archive pages, etc.

Admin Menu on Right vs Conditional Menus