Technically not a "VST," but a stock feature. If you own a Mac, Logic Pro comes with for free.
Let’s assume you use FL Studio, Ableton, or Reaper (which has a free 60-day trial). Here is how to set up a "poor man's Atmos" mix for free. dolby atmos vst plugin free
Use this free plugin to understand how "distance" and "height" affect a sound's frequency response. Conclusion Technically not a "VST," but a stock feature