Platform: iOS, Android
LinkedIn is a popular social network that presents a more professional alternative to Facebook. Most users post information about their work history and resumes. The LinkedIn App for iOS and Android is even better.
The app connects several of your social media tools together. With it, you can be simultaneously connected to Twitter, Facebook, WordPress and other sites. You can also do things like write a WordPress blog post and then let all of your Facebook friends and Twitter followers know about it at once. The LinkedIn app makes sure you're connected with all your networks at all times.