Audio Filters for iPhone Application

We are building a native iPhone app that allows people to send audio clips to each other. We are building the app ourselves, and are setting up everything to transmit the audio clips from user to user. The freelance work we are requesting involves augmenting this audio on the iPhone before it is sent. We are requesting 6 audio filters, each augmenting the user's recorded audio in a different way. Most effects involve pitch shifting, background noise reduction, adding additional audio clips, and more to achieve the desired effect. After providing the technology, the freelancer should also provide a detailed description of how to implement the technology into our native app. There are 6 total effects we want to achieve, and examples will be given for each. Effects listed below: 1. Auto-tune with radio effect 2. High pitch voice effect (like breathing in Helium) 3. Deep voice effect 4. Darth Vader effect (pitch change, add breathing audio clips) 5. Helicopter effect (helicopter background noise, walkie-talkie voice effect) 6. Megaphone effect