I belive we have had "Southern Saints" and "London Saints" for a while. But the current London Saints have been around since an Internet plea for the first TV game v Aberdeen. It ended 1 each with Kirk Broadfoot Scoring after gifting Stevie Crawford a goal.
Since that first day when we had 5 supporters, we have had over 40 different faces through the door. Record night being a Cup Replay in 2012 (i think) v Hearts where the usual corner in the pub we go to was "overrun" with about 29 Saints fans.
We have a flag, you may have seen this London Underground style Love Street "Station". We have presented a POTY award for the last 4 seasons (although we never presented it this year due to it getting lost in the post!!).
We get some tourists too, some that have come to london for the weekend and come to watch the game, or business commuters who happen to be here during the week. We also had the sole member of the Peru Supporters club in for one game when he was in London.
Hope this helps although the numbers involved are small, we are here and we are going strong......