SerpBook (re-branded to Keyword.com) is a paid SEO tool that helps keep track of your website’s rankings for a given keyword. You add the keywords you’re interested in and you can see the progress they’ve made in the last day, in the last 7 days, in the last 30 days and since they were added. If a given keyword has climbed up in search results, it is marked with a green arrow, and if it has fallen, you can see it marked with a red arrow pointing down. You can also see the keyword's monthly search.
You can add some of the keywords as favourites, so that they will be displayed at the top. Also, at the very top there is a table showing for how many keywords your website’s displayed in the top3, top 5, top 10 and top 20.
SerpBook is easy to use and all the information is presented clearly. In addition to the keyword position, it also gives you information on the average number of visitors to your website, average bounce rate or the average time visitors spend on your website. You can also see graphs with keywords to see how they’ve been performing day by day.