Particle Flocker is a particle-based flocking system integrated into Autodesk® Maya®. Harnessing the power of Maya's dynamics systems, Particle Flocker utilises a force field system, allowing animators to apply flocking behavior to any particle-based system in Maya. Particle Flocker is one of (if not the) most versatile and controllable flocking systems currently available for Maya.
Much more information, tutorial videos and documentation can be found at http://www.particleflocker.com
Note: This app uses a custom installer (and not the standard App Store installer).