For the posts screen please use the sample API(http://jsonplaceholder.typicode.com/posts) to display a list of posts.
A post item should show the title and it’s up to you how to display it. When user taps on a post, detail screen should be shown.
On detail screen you should display the post details; the description(body) of the post and the author of the post for which you can use the following API: http://jsonplaceholder.typicode.com/users