Create mobile application for iPhone + android + Web services.

I want to create an app for selling and buying animals where the buyer register by mobile number ( like Whatsapp) , browse or post a listings. Buyers and sellers may contact each other by SMS or Calls, accept or rejects contacts, search, report,comment, add to favorite, etc The seller must be able to post his list with its video/photo uploaded from mobile), categorize it, add its description ( title, sex, type, age, price, etc). The program must work on apple and Galaxy platforms. Note that the app lang. files will be translated to make it dual, English and arabic. I will not do the final payment until the program is working on my mobile. thanks