Voxengo Stereo Touch

Stereo Touch is most effective on monophonic sounds without overly sharp transients: it works great for both acoustic and electric/overdriven guitars, synthetic pad sounds and even vocals. By means of this plug-in you can easily get spacious and even "surround" sounding tracks, without utilizing a double-tracked recording technique.

Basically, the plug-in takes a mono input signal and generates a stereo output signal. Plug-in can also work with multi-channel input signal, but in this case all channels get processed independently of each other like they are separate mono input signals, and then all resulting stereo streams get mixed together to produce a single stereo output signal.