Wave Candy is basically a visualizer of the sound wave coming from a channel.
It can be applied to any channel or the master by adding it to the FX slot in the mixer window of FL Studio.
It can be used to analyze the dB range of the sound wave.
You can take a snapshot of the sound wave at any time by clicking the big Hold button.
It has four modes: Oscilloscope, Spectrum, Meter, and Vectorscope
You could slow down the speed of the wave rendering by adjusting the Update knob in Oscilloscope, Spectrum, and Vectorscope modes.