The iStab is a 3D printed iPhone cover which has a folding knife along one edge, producing a blade whenever you might need one. This phone case is “cutting edge”, and is designed as an exploration in conceptual 3D printed weapons.

The models I based this idea from are free, and the programs needed edit the 3D files are also free.

I love these 3D printing disclaimers: “Blades such as the one shown in this project are considered weapons by law enforcement. This project is provided for educational use only and should not be replicated.”

Uh-huh. That’s why you include material lists, tools and software links.

Via Instructables for the full instructions.