It has two purposes:
1) It aims to correct the 'fault' your listed have and they do this by applying their own EQ setting. This does work for me for number of IEM I own but I dislike what they to do the OrtofonEQ-5
2)It allows you to try to make your currently own IEM sound similar to one of their listed headphone/iem which do not work that good.
3) It will allow you to play FLAC,....files your ipod touch device without needing to convert to other formats.
OK, so based on my understanding after downloading and paying $5 for this app, the purpose of this iPhone App is to simulate the sound signature of the headphone that we currently use against the one that we want / select from the preset.
Selecting the same model of IEM / Head Phone model with the one that we are using, can actually make the sound worst.
correct me if I'm wrong ?