WordPress Meta Robots plugin by destio will give you full control of the ‘meta robots’ tag for each post or page. After activation you will find it as a WordPress typical meta box on the edit page in admin area.
From a dropdown menu you can choose the following options:
By creating an new post/page the default value is automatically set to ‘index, follow’ without any user input.
Download and info: http://wordpress.org/extend/plugins/wordpress-meta-robots/