This is great module Image Speed Optimization and scroll down load product will increase your page speeds and speed rating. Increased page speeds can result in better search engine rankings.

Lazy Loading will increase website speed by loading all the images after your website load completely on customer's end.
Show Animated GIF Image during the loading of your website with each product. You can set time interval to delay in loading images

One Page Checkout / One Step Checkout module is a very simple the checkout process and makes it much easier and faster for customers to buy products at your shop.

This module Delete old or unused data , duplicate Product URLs fix . This module is an extremely good toolkit for your online store , and clean with all function of prestashop . This module will help you everything.

This module minimum Order allows you to create rules blocking orders according to several criteria, by determining a threshold to be reached according to several parameters.

Newsletter Popup is a powerful and flexible module create lightbox popups that help you get more newsletter subscribers, promote new products, deliver special offers. 

Newsletter Popup is a powerful and flexible PrestaShop module to create lightbox popups that help you get more newsletter subscribers, promote new products, deliver special offers. Best module for newsletters.

This module easy to add price .00 and remove in price . Price decimal module also allows store admin to change or delete the decimal number in a price, that displayed in the frontend and backend of your store.

Promotion Popup module displays an advertisement pop-up containing image and text on the website. If the user didn’t close the Ad manually then Ad will automatically close after a time interval set by you

Optimize the natural SEO of your site on all search engines by this modules and you see what is SEO issue in your website products
Find comprehensive search engine optimization (SEO) tools for your site.

Sticky Add To Cart bar - A floating bar that becomes visible either when customers start to scroll/swipe down or when customers scroll/swipe beyond the original Add To Cart button.

This module will help you keep your store nice and clean. Fix bugs, improve performance, make your backups smaller and upgrade process much faster with excessive data removed from you database.