Fabio Policarpo’s Player+ has a polished interface that lets you play music from your iTunes library in much the same intuitive way that Apple’s own iPod (soon to be “Music”) app does, with the addition of a three-band graphic equalizer and a crossfader for melding one song smoothly into the next.

Player+ ($1) provides an attractive oscilloscope-style sound wave viewer too, which helps you figure out where a signal might need adjustment (i.e. the bass is really low, and you want it higher).
When you touch this part of the screen, a parametric equalizer immediately begins to boost or cut the signal, which is a neat way to explore your songs in a new way, and could offer much more flexibility than the apps three-band equalizer does. This feature has potential, but only seems to work while you hold your finger on the screen.
We loved the app’s AirPlay support, which lets you beam music to Apple TV, Apple Airport Express, and stereo systems including these first-out-of-the-gate Denons — a feature that should be mandatory in iPhone music player apps. And the automatic cross-fade feature is a nice way to transition between songs. However, we wish the app included a reset button to cancel out an equalization choice, as well as a way to save EQ changes for later.

That said, Player+ only costs a dollar, while its competitors generally run at least three times as much.