X New Tab Page is described as 'extended application of the browser which is based on HTML5. It offers several features such as speed dial, cloud addition, and cloud backup to enhance the original New Tab function of Chrome' and is an app in the Web Browsers category. There are more than 10 alternatives to X New Tab Page for a variety of platforms, including Windows, Google Chrome, Mac, Linux and Firefox. The best alternative is Humble New Tab Page, which is both free and Open Source. Other great apps like X New Tab Page are Bookmark Ninja (Paid), FVD Speed Dial (Free), Awesome New Tab Page (Free) and Molly (Free, Open Source).
New Tab Override was developed from the ground up as so-called WebExtension. This makes New Tab Override compatible with Firefox 57 and later. Not all options of the previous version are currently available as WebExtension.
This add-on replaces you "new tab" page with what is essentially a clone of the new tab page from Firefox version 30. It also adds functionality for adding, modifying and hiding tiles, as well as a variety of customisations.