aaronfisher

A simple plugin that allows you to include a Twitter feed on any page or post within your WordPress website. All you need to do is configure the plugin with your Twitter handle and your Twitter access tokens and you are good to go, from there you can include <code>[display_twitter]</code> and the feed will appear.
You can choose how many Tweets will appear, whether to include ReTweets in the list, whether to include replies in the list and whether you want to the Tweets to scroll. Selecting the scroll option will set the Tweets to show in a ‘ticker’ style one after the other automatically.
The plugin is designed to be easily styled, we do not include any default CSS so as not to interfere with the current styling of your site. Each Tweet is a simple <code><li></code> element that can be easily styled.

Barebones Twitter

Simple plugin for adding Twitter to your Wordpress install via a shortcode by @AaronPFisher

Edward Caissie

A widget to allow you to set the parameters of the Twitter Follow Button found here: https://twitter.com/about/resources/followbutton. This widget also creates a shortcode that can be used in posts and pages. Also to note, each instance of the shortcode or widget can use a different Twitter name so you can have multiple Twitter accounts listed on your website. Includes support of languages for the Follow Button using the two letter ISO-639-1 language code for English (en), French (fr), German (de), Italian (it), Spanish (es), Korean (ko) and Japanese (ja). 
* Copyright 2011-2015, Edward Caissie (email : edward.caissie@gmail.com)
This program is free software; you can redistribute it and/or modify 
 it under the terms of the GNU General Public License version 2, 
 as published by the Free Software Foundation.
You may NOT assume that you can use any other version of the GPL.
This program is distributed in the hope that it will be useful, 
 but WITHOUT ANY WARRANTY; without even the implied warranty of 
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
 GNU General Public License for more details.
You should have received a copy of the GNU General Public License 
 along with this program; if not, write to the Free Software 
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
The license for this software can also likely be found here: 
 http://www.gnu.org/licenses/gpl-2.0.html

BNS Twitter Follow Button

Displays a Twitter Follow Button; and, includes shortcode functionality.

Barebones Twitter vs BNS Twitter Follow Button