SkyEater OO is a monophonic synthesizer.
You can play melody with keyboard on your mac.
If you want to edit the sound or play multi notes at once, try SkyEater OO Pro (http://itunes.apple.com/us/app/skyeater-oo-pro/id412395544?mt=12) or SkyEater Poly (http://itunes.apple.com/us/app/skyeater-poly/id412780607?mt=12)
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