Lollapalooza, one of the U.S.’s biggest festivals, is just three days away. If you’re planning to attend this year’s multi-day music event and you have an iPhone, there’s some good news for you. There are actually several apps that you can use for your days at Lollapalooza, including the official event guide app. Appropriately called, Lollapalooza, this app includes information on the full line-up of artists, including where they are playing.

You can also see a list of who’s playing in the next two hours, you can see the line-up for a particular stage at the event and sync with your custom schedule from the Lollapalooza Web site.

The Lollapalooza app is free to download from the App Store.

Transportation is always important when attending a large event like this, especially if Chicago isn’t your native city. Buster: The Chicago Bus Tracker will give you the local bus schedule and how long the wait is. This app costs $0.99.

Guide Map Chicago will act as your pocket companion while in Chicago, including the ability to show your current location on the map. You can also access information about taxis, trains, and airports. This app costs $1.99.

Other apps that you can use to gather information on Lollapalooza are SPIN Mobile, a free app; MusicFest ’09 a $1.99 app; and TentFinder, a $1.99 app that does exactly what it says.

If you’re going to Lollapalooza, have fun and be safe.