What is required to create an unofficial app?

Question

Objective-C

Good day! I had an idea to create a client for one social network that doesn't provide any SDK, API, ect. How to implement an unofficial application, what is needed for this?

Answer 1

1. Go to a social network and agree.
Most likely they will refuse, but there is a non-zero chance.
2. If you can't finish it - parse html.
The downside is speed and you will have to update the code when the layout changes.

Answer 2

Understand how it works =)
Parse data and give it to the client.
Question 1. how will you do it - through your server or directly to the client. For example, there is a bunch of extra information on the page, and you just need to tear out the avatar and nickname from there - it’s stupid to give this to the client directly, but by doing so you will create a load on your server directly proportional to the number of users, however, account data will have to be sent through you - it’s not safe .
Question 2. Legality. Some Instagram may indicate in its license agreement that the user undertakes to use only the official application and any use and transfer of data to third parties causes the sixth fleet to the user's shores. Here, by the way, I myself would be interested to hear what they do in these cases. The same unofficial clients