Same problem here.
Plug in installed and activated.
In the Media-Library view, I hover my cursor over the image but the only options are the existing “Edit | Delete Permanently | View”
Please advise. Thanks.
Yes, that’s it. It works with those images that are attached. I just moved site and lost those attachments because I FTPed images instead of going through WP uploader, but menu from plug in shows up on new posts.
It works with every attached image. Before and after the plugin is installed. If the thumbnail is in the media library, and attached to a post, then yes – this plugin should render a link (when you hover that thumbnail) to set it as a featured image.
I’ve just tested this, and no – PNGs are not a problem.
However, I just released a new version (1.1) that might help you. Some themes doesn’t support post thumbnails by default. The plugin tries to add that support if it’s missing, but I’m suspecting I might’ve done it wrong.