Hi Tanuj,
I am glad to know, you would like to build such app.
To be very honest, its not possible as of now because no one can allow it. l mean neither app store nor playstore. Reason : Security breech.
Please be assured to give project to anyone. They may ask you for money in advance and later will not work (as its not possible).
Sorry if any consultation may bother you. Still as a professional entrepreneur, its my responsibility to aware you and educate you.
Thanks,
Manoj Javir
Sr. Project Coordinator.
IWAB Solutions Pvt. Ltd.