GuildWarden tracks and shares your Armour Set and Ward (sigil) unlocks with other members of your guild who also have the addon installed. You can search and filter the database to find people for instance groups, or just to see what your fellow guild-mates have. (Handy note: shift-clicking a class filter is equivalent to clicking the other 11 class filters)

The unlabelled number in the database listing indicates the "handedness" of the data - ie how many people it has gone through to reach you. A 0 indicates your data, a 1 is first-hand data from another player. A 2 would indicate that you haven't seen the player online since their data updated, but that another player forwarded the info on to you. Higher numbers indicate longer chains of forwards in this manner.