Steve

This plugin uses custom fields to allow the page title tag to be customised and differ from the actual page title.
Both meta descriptions and keywords can also be added if required.
Page meta details can be modified on any publicly accessible post type, such as posts and pages, as well as custom post types.
Theme and plugin developers should note that it is possible override the page title within your templates by setting <code>$wppm_title = 'Newly defined title';</code> before the call to <code>get_header();</code>.

Page Meta

Adds the ability to override the page meta title and add in meta descriptions and keywords for pages.

Julian Widya Perdana

Automatically adds keywords and description meta tag on every page based on title, tags, categories, etc. Simple but powerful !
If the page is post, it will sets all title, category, and tags as keywords meta tag. If it is category page, the keywords will be your category name, same work for tags.
It may reduce your work on typing manual keywords every post or even every page of your blog and it is easy-to-use.

Automated Keywords Generator

Automatically adds keywords and description meta tag on every page based on title, tags, categories, etc. Simple but powerful !

Page Meta vs Automated Keywords Generator