iPad 4 track audio player with mixer, tracklist and controls

I need a simple iPad app that will allow the user to select an audio file from a "roll". The audiofile actually consists of up to 5 audiofiles that are played one after the other without any pauses but with a crossfade, and can then be mixed by the user with 1 related audio file and 3 fixed ambient sounds that loops through the length of the audio file. The audio should fade in and fade out at the end. Each of the 4 "extra" tracks can be adjusted in volume and turned on/off. A master volume knob will adjust the output volume of the app. The controls are: play, pause, stop, repeat, increase length, decrease length. Each track has a parameter of minimum length. It should not be possible to adjust the length below that point. And not above 2 hours. The increase/decrease in length is set in 5 minute spans and that will add 1 minute to each file. If a track on consists of e.g. 3 files, then the 5 minutes will be divided in 3 and added to each. Each track has an info field that can contain text, image and url's... url's should just open up in safari. Thats it... Let me know if you have any questions. Payment will be done 100% through Escrow. For the right developer, this will not be the last project - looking for long term relationsship.