Kali/Custom ARM Image
From charlesreid1
Background on the process for generating Kali Raspberry Pi images, using a custom Kali image that runs on Amazon AWS: https://www.offensive-security.com/kali-linux/generating-kali-raspberry-pi-images/
If you give up halfway through, or don't want to bother, you can find a bazillion other OSes that run on the Raspberry Pi: http://elinux.org/RPi_Distributions#DietPi