Handling multiple focus keywords with content optimization is the identity of the Premium SEO Pack. It is one of the best WordPress SEO plugins available. Some of the most useful features include on-page optimization, SERP keyword rank tracking, W3C validator, and 404 Monitor, etc. There are a few known issues associated with the plugin as well, where the most prominent one is that the menu of the plug-in loses on to its UI and shows as plain text. The issue gets fixed only after deleting and reinstalling it, which could be quite frustrating for the user.