ExoPlayer is an application level media player for Android. It provides an alternative to Android’s MediaPlayer API for playing audio and video both locally and over the Internet. ExoPlayer supports features not currently supported by Android’s MediaPlayer API, including DASH and SmoothStreaming adaptive playbacks.
Youtube Player is an open source library that helps you embed a YouTube iframe player into an iOSapplication. Its library creates a UIWebView and a bridge between your application’s Objective-C code and the YouTube player’s JavaScript code, thereby allowing the iOSapplication to control the YouTube player.
Evernote is an opensource SDK that allows the creation of notes using HTML or web contents. Evernote comes with a simple sample application, called (shockingly) inorder for you to easilly access functionality and know your way around it.