The Denon Audio app for iOS is probably the best £1.49 you’ll ever spend on in app purchases.

Denon describe the app for on the go audiophiles. The premium audio player gets the best possible sound from your music library and Tune In Radio. You can create custom EQ curves and playlists.

The EQ is an in app purchase of £1.49. It provides a graphic equaliser for your iPod Music library with 1,000 possible discrete bands. 10 built in EQ bands. Save and create your own. Bypass mode. No spatial distortion.

What this app does is provide a much better EQ calibration and with the headphones I’ve tested it with completely changed them into something totally different for the better. This means not spending another penny on new headphones.

The app does use more battery than the standard built in EQ options.

Very impressed but does beg the question why hasn’t Apple included something like this as standard.

And this is now my default music app. My Sony MDR-1R now have sub bass at levels to smile about !

And then Shaun McGill from Lostinmobile suggested CanOpener which tackles the sound issues a bit differently. First off it fine tunes the sound dependant on your headphone. If they don’t appear in the included list you can add your cans.

The app also has EQ settings for a number of different options.

It also allows you to adjust the cross feed. This is a proprietary algorithm.

You also get tone shaping, a dosimeter and loudness metering to monitor your listening levels and protect your hearing.

For audiophiles it has FLAC support with file sharing via iTunes and uses a 64 bit audio path with sample rated upto 96 khz.

CanOpener costs £1.99 and is highly recommended. It is also a universal app.

I really thought the Denon app was the best but it really is a close call. My suggestion get both. My preferred app is the Denon due to the crazy EQ bass adjustments.