real estate

looking to build an application for real estate..I want users to be able to search all listings in my area (windsor and essex county) ontario. using MLS and be able to give users abilty for driving directions and find the nearest listing to them or arround them for sale or rent. They can search or the gps will automaticly find the nearest listing arround them .they can draw a circle on the map and the app will find all listings in that area or by typing a street [login to view URL] able to see the listing residential or commercial and browse it, share it, save it for later viewing.., I want to add a mortgage calculator to the application where users will be able to inside the listing calculate the monthly payment of the house they are viewing. I wand to be able to send custom messages to my app users about a promotion or seminar or anything else i might be doing, and this could be a message or a picture that comes to my users as a flyer. users must be apple to share the listing with anyone they like on facebook or whatsup or [login to view URL] a section they can send me their digital signature, what i mean is i want to be able to import a picture from my side of the app or computer and able to send it to this user and they can open the file and user their phone or ipad to sign where i want them to digital singing.