There are a few ear training software out there that are worth mentioning.
Here is are a couple of free ear training software for your Mac or PC that can grow your ear without breaking the bank!
Functional Ear Trainer-Basic & Advanced
These two ear training software developed by the same person focus on a specific perception of hearing.
Learn to hear scale degrees in relation to a tonic center with this free ear training software! Although, this software is only for PC, the author has announced that a version for Mac is coming soon!
Download them both here: http://www.miles.be/index.php/software
GNU Solfege
GNU Solfege is designed specifically to train your rhythm, interval, scale and chord recognition skills. This ear training software is basic enough and easy to use.
Download this ear training software for free at: http://www.solfege.org/