WP Post Thumbnail for Pages

After some searching I found an answer to my own question:
http://www.seoadsensethemes.com/wp-post-thumbnail-wordpress-plugin/#comment-412

add this after around line 218 in wppt.php:

add_meta_box( 'wp-post-thumbnail', 'WP Post Thumbnail', 'wppt_template’, 'page', 'normal' );

It adds the plugin’s box to the page´s write panel. You can leave the “filter” at line 218 for posts and add the line above to have the plugin appear on both posts and pages. Or replace line 218 with this one to have the plugin appear on pages only.