I downloaded an app called Yousician. It teaches you how to play basic chords by showing you videos and giving you step-by-step instructions. The app also shows you how to play scales. There's a feature that you can use to tune your guitar too. It uses your phone's microphone to listen to you strum and the helps you correct it until your guitar is in tune. I think the app is really going to help me learn the basics of playing the guitar on my own.