BetabugsAudio has released a public beta version of their latest free VST effect for Window - PhaseBug, a Phase Alignment plug-in.

PhaseBug's primary function is to shift the phase of an incoming audio signal. This is a critical function in fixing source signals that have phase errors in relation to one another, which can cause inappropriate cancellation or reinforcement of frequencies in a mix.

As part of the testing and correcting procedure, a user will occasionally need to sum the stereo signal to mono, which is the surest way to help isolate phase issues. A useful side effect is that PhaseBug may also be used strictly for this purpose - quickly summing a stereo signal to mono.