instant.page preloads after the user hovers their mouse over a link on desktop or starts touching their display on mobile. The plugin uses the following method to start to load.
<link rel=“prefetch” href=“domain.com”>
The 5.0 release added an interesting new feature that allows you to start preloading all the links that are visible in the viewport. This feature could be a nice option if your navigation doesn’t have a ton of pages—the browser can start to preload all of the five most common pages.
instant.page (http://instant.page) is still really lightweight and has a great plugin to add to any of your projects. It is not a one-size-fits-all solution to fix any speed problem, but it is a nice add-on after you have gone through all other optimizations.