FlexSlider is a jQuery-based slider toolkit which is available for use on all major browsers. It is designed to be fully responsive and serves as an easy-to-use plugin. It provides support for multiple sliders for each page along with several navigation options designed to meet different requirements.

FlexSlider also provides high-quality touch swipe support and is known for its responsiveness. It comes with a Callback API as well. It provides navigation of two types, namely, touch-enabled navigation and keyboard navigation. It is also available for integration with Fields and Views. It offers many slide animations and fades animations as well.

AddThis is a privately held company founded in 2004. It is an industry leader in the field of website marketing tools. It works on an artificial platform known as the AddThisAudience Intelligence platform. It offers a wide range of share buttons such as share buttons and follow buttons.
Its share buttons include a floating share bar, inline share buttons, extending share buttons and a share button popup. Its follow buttons are available for free and can be customized and used for analytics as well. AddThis also provides a link promotion popup and slider along with a list building popup and slider. It is available as a CMS plugin for popular platforms like WordPress.

Comparison FlexSlider vs AddThis