We describe a broadband ferromagnetic resonance spectrometer for scientific and educational applications with a frequency range of up to 30 GHz. It is built with components available off-the-shelf, utilizes 3D printed parts for sample holders and support structures, and requires little assembly. A PCB design for the grounded coplanar waveguide (GCPW) is presented and analyzed. We further include a software suite for command-line or script driven data acquisition, a graphical user interface, and a graphical data analysis program. The capabilities of the system design are demonstrated with measurements on ferromagnetic thin films with a thickness of 1 nm. All designs and scripts are published under the GNU GPL v3.0 license.