i am planning on making a button that is when pressed sets an alarm on my phone. I am planning on making an app that is creating the actual alarm, the app just have to be triggerd by the hardwere button.
my question are:
Is this possible without a server (or is there a way to send direcly to the phone, bluetooth maybe?)?
Can the app be triggerd even if it is not running? (the app should just be installed on phone but you dont have to open it in order for it to recive the signal)