The three acts will perform on the same night at the London's Roundhouse venue on September 17.
'Stay Awake' singer Example, said: ''I played iTunes Festival the last few years so it's a pleasure to come back again. I still love the fact it's a free event with such amazing line-ups and in such a legendary venue.''
The two-time chart topper, who has worked with the likes of Wretch-32, Professor Green and Calvin Harris, added: ''It's nice to give something back to all the fans who've bought your album and singles on iTunes.''
Dance-punk band, Hadouken! were also excited to announce their appearance on the bill, and are looking forward to performing their new single, 'Bad Signal' at the event.
The group said: ''We are really excited to be a part of an amazing line up of acts for this year's iTunes Festival. We will be playing a bunch of new tracks from the new record plus some old favourites. It's great that fans can come for free!''
Download the free official iTunes Festival app to see the line-up, apply for tickets, and watch the shows live or on repeat for a limited time.
To register to win tickets, download the app for free from the iTunes store or visit www.itunesfestival.com/gb/win
iTunes Festival 2012, current line-up:
September 1: Usher
September 3: Olly Murs
September 4: Plan B
September 5: Emeli SandÃ©
September 6: JLS
September 8: Jack White
September 9: Deadmau5
September 10: Norah Jones
September 13: P!NK
September 14: Labrinth + Josh Kumra
September 15: Calvin Harris + David Guetta
September 16: Rebecca Ferguson
September 17: Example, Hadouken! & DJ Fresh
September 18: Andrea Bocelli
September 19: Matchbox Twenty
September 20: One Direction
September 21: Jessie J + Lonsdale Boys Club