CoachGuitar is an iOS app which teaches you how to play hits from different decades and genres using a multi-camera video and animated fretboard view. The app is free to download (see http://coachguitar.com/ for links to the App) and you get 2 whole songs and 2 riffs included to get you started.
When you are ready to explore what else is to offer, simply tap on Library and scroll through the 60 or so songs which are available at the time of writing. Each song is an In-App purchase of $4.49 and you are able to preview the track before you purchase to hear exactly what you can expect to learn.
Each track includes a full performance video, a backing track with the guitar parts removed to play along to and a number of videos for each section, Stairway to Heaven for instance has a total of 31 videos included broken up into 9 chapters. Each chapter breaks down a section of the song into small chunks and is played at a slower tempo with the visual fretboard animation to help make it clear which notes to play with which fingers (indicated by the color coding described in the help), which strings to play (realistically vibrate like a real guitar) and the picking or plucking direction indicated at the left side of the fretboard.
There is also a left handed view feature in the settings which flips all of the videos and the fretboard. There are also Loop and Slow buttons, (so if you are really stuck you can just let it keep looping a section at half tempo until you get the hang of it).
If you are finding it difficult to learn new songs then this app could really help you get to grips with the correct fingerings, strum patterns to have you playing your favorite songs from the comfort of… well anywhere you'd take your iPhone, or iPad.