It's good to see that Twitter have finally released an official WordPress plugin to display and interact with Twitter easily on your WordPress site.
Prior to this you had to use there own javascript code (which was pretty ugly and hard to customise) or hack a solution together that often stopped working every six months as Twitter changed their setup or API.
With the release of this plugin it should make your Twitter integration painless and consistent. Yay!
More details at https://poststatus.com/twitter-official-plugin-for-wordpress/
You can download the plugin at https://wordpress.org/plugins/twitter/