IW Magnific Popup

The plugin works out of the box. Just install and activate, and all images embedded in posts or pages will automatically expand using a lightbox window when users click on them.

While there are plenty of similar modal windowing scripts on the WordPress plugin repository, few of them support responsive layouts.

IW Magnific Popup does this because Magnific Popup was created specifically for mobile and responsive pages.

Installation:

Unpack and upload it to the /wp-content/plugins/ directory.
Activate the plugin through the 'Plugins' menu in WordPress.

What is new in this release:

• Modify headers bug fix.

What is new in version 1.2.6:

• Fixed magnifying glass on hover.

What is new in version 1.2.5:

• Small fix.

What is new in version 1.2.1:

• Added alt attribute functionality.

What is new in version 1.1.1:

• Small fix.

Requirements:

• WordPress 3.9 or higher