I have also just tried this. If you add the relay on an iPad, it adds but the app seems to stop working. If you then look on a browser the devices is added with the message Unreachable. If you try to add with a browser, it comes back asking for you to check the addressing.
My apologies that your posts in this thread never got a proper response. I am aware of an issue with adding the PiFace Digital extension via the Android app (see my post here: Piface Digital - #8 by rsiegel ) but neither of you have specifically mentioned that.
If you’re still interested in adding it, can you let me know if these errors are still blocking you two? I don’t see any issue adding this extension via iOS or Web and want to make sure I’m not looking past an issue that still remains on these platforms with this extension.
The issue was when you add a relay widget the addressing seems to be a problem. You see the pi face but when you try save it fails saying it has an issue with the address.