I have been working with this great little app for my iPhone and iPad called Chordbot. It really is a great and simple little application that allows you to get simple backing tracks up and going in seconds. I highly recommend checking it out. You can really take your practice portable as this app. Using just the device’s speakers and an unplugged guitar, you have a perfect neighbour-friendly practice tool.
BTW – I have ZERO affiliation with these people, just passing it around as I have found it something worth sharing. Check out their site (http://www.chordbot.com) for a full rundown. It has loads of features.