Manual EQ on iOS

Is there any way to do this? My new headphones are bass heavy. I am able to mostly compensate using the "Treble Booster" setting, but would like to do better. I can manually adjust the EQ in iTunes on my Mac and save the profile, but it doesn't get synced over to my phone. Is there any way to do this? Any decent app I can put on the phone? Oh, and why does it take 4 seconds for changes in the EQ settings in iTunes to take effect? My old analog EQ on my stereo works instantaneously. Super fast computer takes 4 sec. What gives? That 4-second delay makes it much harder to EQ.