Electrocap is a freeware modelling an electrified droplet at equilibrium and wetting a solid surface. The model consists to seek the drop shape by minimizing its total energy (capillary, electrostatic and gravitational). To this end, the model is based on the classical shape optimal design method. In this paper, we derive the equations and the shape gradient; we detail the shape optimization algorithm implemented and present some numerical results. The code is based on the public mesh generator Bamg and the public C++ finite element library Rheolef.