Modules for Backdrop CMS

The Flickr module embeds images hosted on Flickr with a link to the
corresponding Flickr page.

AutoFloat

This module contains helper functions for Backdrop developers. It provides a
wide array of tools for examining the functionality of your site, including:

Libraries API provides external library handling for other Backdrop modules.

This module is a port to Backdrop of the Drupal contributed module 'Commentsblock'.
It puts the comments and the comment form from a module into a block which can then be placed
in a different location within a layout.

The APC module integrates the APCu extension with Backdrop CMS as cache backend.

Requirements

A light-weight, customizable lightbox plugin for jQuery 1.4.3+. Iframed or
inline images or content can be displayed in a popup or modal "lightbox" above
the current page.

The Colorbox module:

Webform Remote Post is a module that works along the Webform module. It eases the integration between Webforms and other web applications (including systems like Salesforce and Eloqua).

DISQUS is a third-party comments platform that helps you build an active community from your website's audience. It has awesome features, powerful tools, and it's easy to install.

Display recent comments, popular threads, and other widgets in blocks

This a simple module that allows you to set a vertical parallax effect on the background of any element on the DOM.