Bear
Bear is a low-end enhancer plugin that employs the principle that you will perceive the fundamentals as louder if you add or enhance the harmonics of a signal.
$5
Noisebud
3 products
Effect
Bompa
Bompa was created to do everything that you shouldn't do to audio in one highly effective mayhem plugin.
$599
Utility
Binvert
Binvert was originally meant to be a plain mix tool to handle phase problems when mixing several bass heavy channels, but the users seemed to use it mainly to deepen or sculpt the low end. Development have therefore been focused on the usability as a bass sculpturing tool even though the original functionality is still there.
$39