Dear Sir,
I have read your Project Description but do you have more detailed requirements, some reference/example App URL or you can drop me a message thru' Freelancer PMB, so we can discuss the requirements & come up with our estimate in terms of time & cost to move forward. As you know that without having detailed requirements, we cannot estimate it, so please ignore our current bid, as it is just a placeholder.
Look forward to hearing from you.
Regards,
YK
LEADconcept