Azertopia has released ADopplerEn, a classic doppler effect. It combines a pitch shifter and a rotator to reproduce the effect a static listener can hear when a train or a car is moving fast. It is based on two synced LFOs with an adjustable phase difference which can be synced to the host.

ADopplerEn is available for Windows as a VST effect plug-in. It is released as donationware, free for non commercial use.