Hi, there - my name is Amin, came from America.
I've read your brief and can see that you'd like to build an Android and iOS app, based on analysis of requirement and from my experience, I offer $10000 / 60 days.
Milestone steps:
1st - App design in PSD format.
2nd - App front end development based on approved app design.
3rd - App back end completion
4th - Integration of front end and back end.
Of course, my offer is a bit higher than other freelancer's bid, but when you think about the high-quality product for your successful business, I think it's a correct time and reasonable budget.
I am extremely experienced in iOS and Android app development with 10 years and I am also very strong at server back-end programming, as well as synchronizing app and MySQL database by developing and integrating JSON-RESTful server API modules.
If you'd like to take a look at my previous works, please check my freelancer profile.
https://www.freelancer.com/u/aashshak
I will do my best in order to realize your ideas into reality.
Please contact me, I hope to discuss this job more details.
Thanks and best regards, Amin.