Hello Sir,
I have read your requirement and I would like to go further on this.
Let me introduce myself, I am Angel (skype: proejct4angel) working as freelancer on Android and iOS with team of 7 persons. You can see some of my previous work in my portfolio.
Sir, I understand your requirement points from 1 to 4 and I can provide you perfect solution in your budget. Sir, I would like to request you to lets have some words via chat before you choose any freelancer for this task.
Looking forward from you.
Regards,
Angel.