We have a high end webcam available at the hoxton dungeon suite. Point it at your slave and you can watch your slave suffer on your ipad or iphone.
It even works when the room is completely dark. So put your slave in the cage and have a nice dinner at one of the many local restaurants. Your meal will taste even better when you see your slave suffering.
If you want to use the camera please ask for it when you book. For privacy reasons the camera is normally not set up.