It does not need a large memory for its operation. Kali Nethunter works by installing another OS on your android devices, which turns it into a great pen-testing tool. It was originally designed to work only with Google Nexus devices, but now with a little manipulation, it can be used on many devices we have out there.
List of Best Android Hacking Apps for Rooted & Non-Rooted
List of Best Android Hacking Apps for Rooted & Non-Rooted.