What is reiner transfermarkt?

As an AI language model, I do not have the ability to browse or access external websites such as Transfermarkt. However, I can provide general information about Transfermarkt, which is a German-based website that is considered the largest online marketplace for football transfers. The website allows users to track and analyze player values, transfer rumors, and contract information across different football leagues and teams around the world. The website also includes in-depth statistics, profiles, and rankings of football players, as well as features for users to create and manage their own fantasy football league.