This work presents the development of a wireless Access Point (AP) placement software that uses microwave signal propagation models. We use the Simulated Annealing metaheuristic, to improve the signal coverage according to the physical features of the architectural floor plan. In the experiments, a Graphics Processing Unit (GPU) with CUDA is used to parallelize the simulations, speeding up the runtime required. It is worth noting that our software makes possible to test the provisions of APs without the operational cost of having to move them physically. It proposes a spatial arrangement of APs that provides a greater coverage with usable signal intensity within the simulated environment. Using a limited amount of APs, the test case results showed that it is possible to obtain a significant improvement in the coverage of the Wi-Fi signal by adjusting the APs positions to the metaheuristic proposed solution. In addition, our software is capable of performing simulations with an increasing number of APs if the current quantity is not enough to achieve better quality and signal coverage.