Write an server frontend iPhone application -- 2

We're working on a music composition web-service that we want to demo with a simple, elegant iPhone app. Development deadline is the beginning of may. The app would have 4 or 5 views. We're looking for a freelancer or a small team with great iOS development and excellent UI/UX design skills. We are looking for freelancers in the time zone of Bay Area (PST) or Central Europe (CET). The app main functionality is recording and playing back sounds, listing users, FB authentication, FB sharing and REST API communication. All audio processing is done on our servers. The app does not contain any audio logic beyond playing back and recording audio files. In short, it's a thin client. The main goal of the app is to provide a slick UI/UX experience. We require an outstanding, state-of-the-art, yet simplistic design in the fashion of iOS 7. Because of the simple nature of our app, we don't expect the design to be overly complicated, but we want to emphasize that we are looking for someone who pays great attention to details. Naturally, we also require that the developer has experience with Core Animation. We will provide a company logo and a company color guideline to the designer. Your proposal must include the possibility of iterations on the design that incorporate our feedback. (hence the higher budget). We don't provide any other design assets or an app icon, and ask you to design it for us. The project starts ASAP, but no more than a week from now. Even though we have specified a high budget, we don't necessarily intend to use all of it for this demo app. The right price for this project is a fair price, and highly depends on the references you can show us. Please come back too us ASAP introducing your team structure, skills, experience, your proposal for a fixed price, and a link to your portfolio.