Chat Application Similar to Facebook Messenger

To build a iPhone and Android Chat Application (Similar Facebook messenger with VoIP call functionality) and a synchronized Website with web chat (Facebook Web Chat) Here are the requirements: 1. User can register and the site will have a user database with their contact, DOB, address & other generic information 2. While registering user should enter their mobile number and an account confirmation SMS (with a PIN code/OTP) should go to registered mobile number. User should enter this password/PIN for first time login 3. If User is registering from the Phone (download app and registers from there) then an SMS should be sent to phone (exactly like it happens for WhatsApp) 4. User should be able to pull his/her friends/contacts from other accounts like Hotmail, Google, Yahoo, etc. Like when we create a new account on Facebook, Gmail, etc. it allows the user to pull friends/contacts from other accounts 5. User should be able to pull contacts from my new site to his/her other accounts like Hotmail, Google, Yahoo, etc 6. There will be an iOS/Android app also which will use the same login/credentials as created on this website 7. User should be able to access all the information in his/her account on his/her phone app as well 8. User should be able to chat either from Phone App or from Web Chat 9. User should be able to access chat history on both Phone App & Web Chat 10. Both Phone App & Web-chat should be synchronized in real time 11. If there is any update/changes on the App or on the web login then should get reflected on the other 12. Website and app should be completely secured (128 Bit SSL Encryption) 13. We (Developer & I ) can discuss and finalize the UI design of Website & App 14. I would like to get all finalize and see all the design documents (including database design/schema, features design and flow design) as first milestone. Once we finalize the design, Developer should start development on subsequent milestones/deliveries. 15. Final working code will be delivered at the end of project and will be property of employer. Employer/I will have full rights to change, distribute, extend, reuse that code without any permission from developer(s) or anyone else 16. With delivery of final code, would also like to get a test documents/reports providing information on what all tests has been run and their results 17. Would like to also understand what type of code support after releasing the final code will be provided? What type of bug fixing and for how long?