There have been several apps designed to enhance the experience of listening on headphones, using a variety of digital manipulations of the signal. CanOpener is a new entry in the audio app derby, and it's a solid debut.
CanOpener is a U.S. $4.99 universal app with an extensive feature set. A Crossfeed feature lets your headphones sound a bit more like speakers, by blending the separation in adjustable amounts. An equalizer gives you a large range of settings to fit the music to your preferences, and a Dosimeter lets you know how loud the audio is to protect your hearing.
The app also supports gapless playback, and can handle sample rates up to 96 kHz. Channels can be reversed, along with phase, something I don't see in similar apps. It
