I want to create a simple app like Shiritori Manzai.

Currently using Swift2, I have finished one and a half reference books for commercially available application development. I'm a beginner in programming.
I am currently trying to copy existing apps for private practice.

So, I have a question. If you want to create a post type that first logs in on Facebook or Twitter and posts (exchange information) using that account in the app, could you give me a quick hint on how to do it?

I'm thinking of creating a simple app like Shiritori Manzai in the existing app.
I was able to post in-game results on SNS using the Social framework.
I want to try the opposite.