Maybe make some explosives that when you make them, you have the option of having a signal receiver Or something else that you can attach to it and also make a remote detonator for the bombs to make traps or get further away before they explode.
Yes please. Or at least explosives with a settable delay.
It’s called a C4 detonator, FYI. 
Not really sure why it’s a ‘C4 Detonator’ rather than just a detonator.
A detonator can be a cell phone, watch or an actual purpose-built signaler for detonating explosives.
Yes, with two phones this is easy.
Get the receiving phones number, then open the case of the receiving phone. Then pull out the cord connected to the earpiece and hook it to the explosive.
Call the number and you accidentally forget which explosives number you called. A C4 explodes in your pack! You Die!
“Mobiles” and watches and even that thingie on your water tank are all timers. Detonator is on the explosives. Your abbreviated “remote detonator” is a remote, radio controller. F**k it up, and some college kid will set the bomb off while you’re about, doing his show in frat’s dorm. Or that brat with an RC car.
Guess the ability to be cool lays in the fact that you can blast a metal door over a GSM network in a terrorist-polluted world.