Projet VoIP pour iPhone/iPad

On behalf of one of our client, we are looking for an iPhone 4/5 & iPad developer in order to take over a VoIP project.
The project is already partially developed.
The project is based on an open source (Linephone) from BelleDonne Communication.
The objective is to customise the application by:
- Changing the look and feel of the application.
- Removing some existing features and adding new ones.

The study has been done with mockups and time has been evaluated to around 50 days.
Due to the nature of the project and the work being a distance work, the developer will have to be able to test the application on iPhone 4, iPhone 5 as well as an iPad.

The developer will have to:
- Install the current project ( based on linephone open source ) for iPhone + iPad
- Acquire enough LinePhone code source knowledge to be able to modify and add our features.
- Update the look and feel of current product (a designer will provide all materials)
- Develop all features
- Participate and organise testing

Features are:
- Registration process using dedicated server (restful API) and dedicated VoIP server
- SMS Opt-in registration system
- PhoneNumber based identification with real number and virtual Numbers
- Extended profile information ( photo )
- Recommend product to friend by sending SMS
- Centralised phone book (allowing to get public photo and connected status of user existing contact, like Whatsapp)

Some of the features have already been developed partially.
English is mandatory.

For confidentiality reason, details of the project will be given to a first selected set of propositions.