The button can be put into any case as desired, of course; it's just a switch. Not sure about the buzzer; those can get annoying. But if the HTTP request gets p

The button can be put into any case as desired, of course; it's just a switch. Not sure about the buzzer; those can get annoying. But if the HTTP request gets proxied through a little server on the friend's machine, then the server can play a nicer confirmation sound, add notifications, etc. as needed. But yeah, if they want full wireless, a USB battery pack will do the trick.