I have installed your app and I can for now make the following comments.
The app feels a bit heavy and takes its time to show something... I would recommend a "loading" screen.
Overall Grafics are very good, but user interface , for me, looks a bit over dimensioned... I would make user interactive feature smaller and give more emphasis on cover art.
[You should set an option to change the oscilloscope visual effect to a VU graphic for example... It's less "annoying", more user friendly as most can relate to such graph, and more smooth.]- it was only AFTER seeing the video that I noticed the additional features... Most users won't see the video and my pass their trial period without even noticing these features.
User interface is somewhat cluttered. Audiophiles don't like to keep messing with controls, they like to have control... Different things.
Your notification visual is a bit over a called and the << and >> buttons seem stretched.
Every song on my song list shows negative times and over one hour duration, this is a probable bug(?) ie Mins -1:00:04
I also think 7 days is kinda short as to make someone buy your app, and +5€ is a bit expensive given other apps pricing.
These are my personal opinions and in no way should be viewed as denigrating... I tried to be as objective and constructive as possible.
I would give it a 4.5 star rating.
I tested it using my 7" Asus phonepad