This program explains how to programmatically assign related products magento 2.
Programmatically add multiple images magento 2
This tutorial explains how to programmatically add multiple images Magento 2. The additional images are reading from the CSV. I have downloaded the additional images from the remote directory.
Add image block shopify theme
This tutorial explains how to add image block shopify theme and make the blocks editable from the backend. Here it create a section in the backend where you upload the image and linked that to the collection.
Add content block homepage shopify
This tutorial explains how to add content block homepage shopify. Here it explains how to create editable content blocks.
Sliding contact form magento extension
The extension adds contact form slider as shown below.This is a free sliding contact form magento extension.
Also refer how to extend contact form and save contact details and other magento extensions.