The invention relates to a device (10) for producing milk and/or milk foam able to be used as a standalone device or used wirelessly connected to a beverage preparation machine (20); the device (10) controls the characteristics of the milk and/or milk foam desired, when this device (10) is used as a standalone device; the device drives the beverage preparation machine (20) when connected to it wirelessly, for the preparation and dispensing of beverage recipes prepared in conjunction with this beverage preparation machine (20), managing sequences for arriving to a desired beverage recipe. The invention further relates to a system comprising a device (10) for producing milk and/or milk foam as described, and a beverage preparation machine, the device (10) being wirelessly connectable to the beverage preparation machine, the user selecting a recipe in the device (10) and, depending on the recipe selected, the device (10) works as standalone and produces the said recipe or it drives the beverage preparation machine managing sequences for arriving to a beverage recipe as provided by the user's input. Furthermore, the invention relates to a method for operating a system as the one described, in order to prepare a beverage or beverage recipe.