The Star Ratings plugin will allow you to add a star rating system to Question2Answer website. The plugin offers great customization options to fit individual requirements to the setup Star rating system for q2a site.
Q2A Developer can extend or place the star rating at anywhere in the theme.
Important Note: Next version is going to be released very soon in a month or so. Please make sure you must update your existing plugin to the latest version. The next release will have major database upgrade.