WoWreader is an application employed by Allakhazam to collect data from World of Warcraft.
WoWreader installs on to the players computer as a windows application, and a regular WoW AddOn.
Each time a player logs out of World of Warcraft, the addon will save Player data such as Equipment and Bag items, but also items from monsters that dropped during the session.
All these data are then parsed and uploaded to Allakhazam, when the player chooses to run the WoWreader windows application.
Players are afterwards able to link their World of Warcraft profile from the Allakhazam website.