Seodev

SEO Tool which replace titles on selected pages and posts. Also adds ability for meta description.
<h3>Important note</h3>
This plugin uses “Session Buffering” to work with some websites (for forcing replacement of titles). This means that if your host / web server uses a cache service there is a possibility that a conflict might occur. We give no support regarding host / web server support to avoid this.
<h3>Planned changes</h3>
In the future we plan to change the backend overview and settings page so it will use WP Table structure instead for better handling.

S-DEV SEO

SEO Tool which replace titles on selected pages and posts. Also adds ability for meta description.

hitmax1978

Find the post. Click “Edit post”. Activate the “Text” tab of your post.
To modify the title tag of your post, add a simple string into your post content: 
<!—title=”your title”—> (See screenshot-1)
To modify the description tag of your post, add: 
<!—description=”your description”—> (See screenshot-1)
IMPORTANT!!! Be sure after “<!” characters you have two “-” characters. It is similar to HTML comment tag.
Multilingual support
If some kind of multilingual plugins are active (for example Multilanguage by BestWebSoft) – you can define titles and descriptions in other way: (See screenshot-2)
English locale (United States) 
<!—title_en_US=”your title”—> 
<!—description_en_US=”your description”—>
Українська локаль 
<!—title_uk=”Ваш заголовок”—> 
<!—description_uk=”Ваш опис”—>
Русская локаль 
<!—title_ru_RU=»Ваш заголовок»—> 
<!—description_ru_RU=»Ваше описание»—>
Feedbacks are welcome. Visit <a href="http://onlineservicetools.com/meta-tags-from-content-wp-plugin-discussion-feedbacks" rel="nofollow ugc">onlineservicetools.com</a>

MetaTagsFromContent

Good in multilingual site

Generates title and description tags from post's content.

S-DEV SEO vs MetaTagsFromContent