Zend certified PHP/Magento developer

Raspberry Pi how to stop running apps with keyboard

I have an app running at startup with raspberry pi

I set /etc/dhcpcd.conf to use static IP, but it doesn’t work, it keeps on changing

I also have an app that starts up automatically

So now I cannot SSH into it, and I cannot check or change the IP manually because I have an app running

I can plug the keyboard into it, but I can’t exit out of the app with keyboard.

I can hit ctrl+alt+del to reset it, but ctrl+c doesn’t work

For now how can I stop the currently running app (started with init.d) in the background, so I can at least check the IP

Bonus question, how can I make sure that the pi has a static IP every time.

Thanks