Well, first things first, that's great app, either for home and outside (read pranks) use For me that arbitrary button is spot on idea.
I do have one request, I don't know is it hard to get new devices on app, but if it is ok for You to add this one:

"TRIAX Digital Satellite Receiver SR 110"

Living in Eire, and there is plenty that stuff around, have one (this is very cheap, and low end stuff - but working fine) myself.

Keep up the good work.