Develop VOIP application using twilio APIs

Hi, I am looking to start a new brand. Starting with an android app which can use [login to view URL] APIs to call/sms to any number. The idea is to make it big brand and provide with the lowest possible rates for the people to communicate. I have made an account in [login to view URL] and I have put some balance too for you to test things up. I will give my login credentials to the successful freelancer and you are required to make use of the APIs given. Previous experience with [login to view URL] is highly prioritized So, Basically I want an expert to develop a complete android application for me which works as VOIP application. People can download it free from playstore and then purchase credits to call their loved ones. I am looking forward for any suggestions from you guys too. Any nice suggestions are cordially invited. Please tell me what you can do to put the building block of this brand. I am looking to expand it afterwards to IOS and then web application too. I would love to work with someone who can work for us until the end Please read the description carefully and only bid if you can really do this. I am not very keen of changing my team in the middle of the project so I would love to stick with the person developing android app, for the rest parts of the project too Thanks