* Financial Domination is an obvious one.  Whether it's handing over cash or handing over control of a bank account, there's real actual financial pain possible without being in the same room as the fag.

* Remote control chastity.  The key to the device can be locked in a box controlled by a bluetooth padlock.  The fag may have the box, but there's no way it's getting the key without the Master's say so.  

* Remote control butt plugs.  Sub has to put it in, but then its arse is under remote control.

* Online cameras.  Fag's house becomes the big brother house.  Master can set all kinds of rules....

* Amazon Alexa.  "Drop in" allows instant access to someone else's Echo -- voice call and microphones.  Speak and hear what's going on.  Great in combination with the cameras.

* Tracking apps.  Use the fag's phone as a tracking device.  Endless possibilities.

I fucking love technology.  I fucking love control.