Monomaker is a simple mono-merging and stereo-recentering utility plugin.
You can use the mono merge parameter to progressively merge your stereo audio channels into a single mono signal. Turning mono merge all the way up to 100% will make your sound completely mono. Turning mono merge all the way down to 0% will leave your audio unaffected.
The monomix mode parameter let's you select whether mono merge is performed with equal power mixing (which tends to retain perceptual volume level while merging channels with differing audio), or linear (which is simple summing of channels and retains exact volume levels when the channels contain identical audio).
You can then tilt your audio more to the left or right using the pan parameter. The panning is equal power (meaning that as you move further over to one channel, sound is rebalanced in order to keep the total volume consistent).
That panning volume rebalancing strategy can be selected with the pan mode parameter. In recenter mode, as you pan further over to one direction, sound from the opposite channel is copied over to the first channel, retaining the overall volume of audio from each channel's input. Balance mode increases the volume level of one channel's audio when panning towards its direction while reducing the level of the opposite channel.
Also, in case it's useful, you can re-route the two input audio channels in a variety of ways by using the input selection parameter. "Left-right" means that everything is normal, "right-left" means that the left and right channels are swapped, "left-left" means that you lose the right channel and get the left channel copied to both inputs, and "right-right" means that you lose the left channel and get the right channel copied to both inputs.
Monomaker's signal path is input selection first, then mono merge, then pan.
Monomaker can be operated with a mono input / stereo output channel configuration, however in that case, only the pan parameter serves any function.