Woocommerce is an open source WordPress plugin to build own online store. Woocommerce is the more popular eCommerce solution.It comes with many short-codes that help to expand functionality. In admin we have an option to add products.
Watermark text can we added by using php image library such as GD and Imagemagick
You can download files directly using url or you can your files server to server using following code
FPDF is php class that is used to generate pdf in php. IN FPDF F stands for free it means you can use or modify it accordingly.
Bootstrap is an open source framework to create responsive, mobile friendly sites. It contains HTML and css based design templates for website interface.It is free to download and use. In bootstrap 4 there are various predefined classes for padding and margin to improve the element’s appearance.
WordPress comes with many hooks, hooks are functions that can be used to an action or a filter.For adding text after WordPress content we also have a filter.
User agent is a string that help us to identify the current browser.
Facebook is the most popular social networking site. Facebook provides graph api to get data . We can fetch Facebook profile data using JavaScript also.