Twitter has just released its own original Share button. And this plugin simply adds this button to the end of your posts.
To avoid the errornous issues, the plugin adds the button at the end of the posts ONLY in the individual pages of the posts (and pages). If you want to add the button wherever you want in the post,
check out the shortcode version of the plugin.
The plugin works fine but it has no options or something else that you can tweak. However, it will be constantly developed.