I need to find out an approximate cost of developing a smart phone application to make doctor's appointment online. I have a web site with MySQL DB that stores doctors and their availabilities. The smart phone app will allow users to search doctors by zip code, show schedule (availability) of a selected doctor and provide interface to make an appt.

does anyone know how much would it cost for a) Android b)Apple platforms?

Thank you

Considering I make apps, the cost varies just like a website.

You shouldn't pay more for an Android app than an iOS app. They can be coded and ported.