stylobox is a free rompler VST plugin developed by acid.milch&honig. Compatible OS(s): Windows.
stylobox is like a virtual analog or physical modelling emulation of a well known toy instrument classic. It works without any samples, so octaves are possible. The only parameter is the vibrato on/off switch, which can be used with the mod-wheel.
http://acidspace.acid-milch-und-honig.de/