zackproser

The Simple Twitter Follow Me button allows you to add a small or large Twitter follow button to the end of every post so you can grow your Twitter following with your blog readers and let your audience easily share your content on social networks.
Once installed and activated, go to Settings -> Reading and scroll down to the Simple Twitter Follow Button settings.
Here you can enter your Twitter username and choose whether the button should be small or large.

Simple Twitter Follow Me Button

This plugin is the easiest way to add an official Twitter follow button at the end of every post so your readers can follow you on Twitter.

antonpug

This plugin adds a customizable Better Follow Button at bottom right corner of your Jetpack-powered WordPress.org site.
The plugins integrates with the built in subscription manager of the Jetpack Plugin to collect the email of the subscriber and handle distribution of new posts via email.
NOTE: This plugin requires the Jetpack plugin to be installed & activated
For further information visit the plugin website.

Better Follow Button for Jetpack

Adds a floating subscription button (like on WordPress.com sites) to Jetpack-powered WordPress.org sites.

Simple Twitter Follow Me Button vs Better Follow Button for Jetpack