Gain Tracker tracks gains achieved in World of Warcraft and provides aggregated statistics.
Currently, Gain Tracker tracks gains in XP and Gold. These gains are further differentiated per class, talent spec, zone, level and rested state. In addition Gain Tracker also tracks the time spent to achieve these gains. With this information Gain Tracker can for example tell you where the most XP per hour is found for Level 42 Mage.
Gain Tracker works by an in-game addon that records gain data. This data is then uploaded to the Gain Tracker web site. Data contributors get a detailed personal report on the gains they have produced with their characters right after the upload. Apart from that, the Gain Tracker web site displays data only in aggregated form.
Future plans for Gain Tracker include more and improved statistics on the web site and tracking additional information, such as the announced PvE points.