Last time I looked in to this (many years ago) the only way you can use software that reboots an Android phone is to have that software signed with the same key that signed the firmware running on the phone. [0]
Sadly, it's not straightforward to make a remote reboot-phone button that's usable by the general public.
[0] IIRC, calling halt(8) from the shell didn't work, either.
Sadly, it's not straightforward to make a remote reboot-phone button that's usable by the general public.
[0] IIRC, calling halt(8) from the shell didn't work, either.