Indeed, and if it stops working, debugging the wire will be much easier than reverse-engineering an obsolete mobile application.

If you need wireless and are not adverse to some tinkering, a pair of Arduinos, a button, a buzzer and a pair of RF 433MHz transceivers [1] may do the trick!

[1] https://randomnerdtutorials.com/rf-433mhz-transmitter-receiv...