The cell phone operating system we all know in love, Android, is based on Linux. With its relative open sourceness we are able to load whatever custom rom we like on our devices. Not long ago Ubuntu released their own Rom for Android devices. Jola is in the process of releasing SailFish OS to Android devices. Companies like Cyanogen Mod and MIUI were birthed out of creating custom OSes for the Android platform. Kali Linux has released their own rom named "Nethunter" which focuses on security of networks. This rom includes some browser tools that can be used to hack wireless networks and computers. Nethunter is enables your phone to emulate a USB human interface device, launch keyboard attacks, and includes a BadUSB's man in the middle attack. This will only be available for Nexus devices. The team aquires its kernel sources from Google. This is however open source so it could be ported to other devices. This is obviously not meant to be used maliciously, but rather for security reasons so you can find and patch holes.
Via Rootzwiki