Simpson's rise to recognition was featured on The 7. 30 Report in December 2009. He released his debut single, "iYiYi" (which features American rapper Flo Rida), on 15 May 2010. The music video for Simpson's second single, "Summertime", was released on 20 September 2010. Simpson relocated to Los Angeles in June 2010 with his family to record his songs with Atlantic Records' Shawn Campbell. That same month, Simpson appeared on Sunrise. On 22 June 2010, it was announced that Simpson would participate in the Camplified 2010 Tour, along with other artists, touring across the United States. The tour began on 5 July 2010 and ended on 14 August 2010. Other tours that year included a middle school tour that took place from October–November 2010 and covered 9 U. S states. An EP, 4 U was released on 21 December 2010. The EP included five tracks in total, four of them being previously unreleased. Simpson recorded a remake of the song "I Want Candy" by The Strangeloves as the main theme song for the Easter-themed live-action/CGI-animated film Hop. In May 2011, Simpson was "egged" during a live performance at Westfield Miranda in Sydney. Simpson told Australian radio show The Kyle & Jackie O Show that he was not in fact hit by the eggs, and that he was upset on behalf of his fans because the remainder of his show was cancelled because of security concerns. He then started the Waiting 4U tour with American singer Greyson Chance on 9 April in Ivins, Utah. The tour ended on 18 May 2011, in Portland, Oregon.