Twitter Kit is designed to make interacting with Twitter seamless and efficient. Displaying Tweets, logging someone in, or Tweeting from your app is all made easy with Twitter Kit's components. Twitter Kit provides views for Tweets and live timelines, and a composer that makes sharing from your app simple with a few lines of code.
The VK SDK is a iOSlibrary for working with VK API, authorization through VK app, using VK functions. To authorize via VK App you need to setup a url-schema for your application, which looks like vk+APP_ID (e.g. vk1234567).
The LinkedIn mobile SDK for iOSdecreases your app's time to market by providing out-of-box support for LinkedIn natively inside your iOSapplications, saving you time to work on the unique parts of your application that matter the most. The LinkedIn SDK provides single sign-on (SSO) authentication, in conjunction with the official LinkedIn mobile application, a convenient wrapper for making authenticated calls to LinkedIn's REST APIs, deeplinking to additional member content in the official LinkedIn iOSapp, and a sample application that demonstrates all of the SDK's features.