If you're an aspiring guitar or bass player looking to quickly learn a song, tabs are by far the quickest and easiest method. The ultimate-guitar.com app takes the massive database of tabs from the website's online database and catalogues it in an easy to read way, so you can pull out your iPhone, search for a song, and starting playing along anywhere. You can even set the tab pages to auto-scroll at varying speeds as you play, which helps tremendously. It's also worth mentioning that from within the app you can purchase the "Ultimate Guitar Tools" pack, which includes a guitar tuner, metronome, and chords library that will then be integrated within the normal app. If you find yourself using the app a lot while playing along with songs, it might be worth it.