Necessary base for creating a social iOS application

Question

Software design

Hello, I want to create a small social application for iOS (yes, everyone is like the second Zuckerberg) .
I want to implement the following functionality:
1. Verification of the phone number (sms at my expense) - here the question of how to add this to the application is of interest? I would like to hear examples from personal experience of use and approximate prices.
( maybe some services provide some sort of API? ).
2. User uploads of their photos: how can this be organized?
( I don’t really understand this issue, but, apparently, I will have to raise a server on which all this will be stored )
3.Using geolocation in iOS applications: how can you determine which users are nearby?
( apparently, there is some function in the iOS API, but I didn’t find something, or maybe it’s not there (: )
I would be very grateful for any advice, because the first project :(

Answer 1

1. I once used http://www.napishi.ru to send SMS, there was a very simple api, the ability to substitute your text instead of the sender's number, it seemed inexpensive
2. how not to answer without your own server at once
3. in api ios, you can take the current coordinates of the user, transfer them to the server, which will already count who is nearby