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.

digitaldali

SEO Images that work helps you get a major SEO boost by adding Alt and Description to all you IMG tags. 
All the magic is made on the fly and no database changes are performed.
Made as a 20% time project in <a href="http://digitaldali.pro" rel="nofollow ugc">Digital Dali</a>

Simple SEO Images that work

SEO Images that work is a simple plugin for automatical adding Alt and Description tags to all images on your Wordpress website.

Page Meta vs Simple SEO Images that work