Works as advertised Avaliado em 5 de 5 estrelas

but shouldn't the grey-white bar at the bottom (x-axis) be colored?

At least it woud be a good idea to add an x-axis and y-axis including the basic unit and that are scaled for reference. Otherwise you can't even estimate the frequencies that match a peak value.

Esta avaliação é para uma versão anterior do extra (1.0.0).