Add Whatsapp share to wordpress site

A simple requirement for Wordpress experts. I need someone to add a whatsapp share button to my listings at [login to view URL](.)in It should be displayed in single listings as well as in archives. Single listing sample page: [login to view URL] Archive sample page: [login to view URL] The Button should be purely CSS (with no images) with a green tinge in the background & white text "Whatsapp it!". Style should match with the existing buttons in the page. The button should be displayed when viewport size is < 600px ONLY. The whatsapp functionality should work for Windows OS, iOS and Android OS's. It should share the listing Title, Location & URL to the intended recipients. I need an option to suffix a text/image to the whatsapp share. This can be hardcoded (HTML string in the code itself, no need of frontend entry, I will edit the code when necessary) and it will be used as a signature for all whatsapp shares in the site. e.g. Dominos, New York - [login to view URL] --Powered by [login to view URL] In the example, Second line is the proposed HTML signature. Preferred location of the Whatsapp button is marked in the images attached.