Complex sentence: New York City, and Washington, D.C. Crowds on Demand was founded in October 2012 by Adam Swart, who says the idea came to him when, upon disembarking from an aircraft on a trip to Estonia, he wished for a crowd to cheer for him.
Split into simpler sentences: New York City, and Washington, D.C. Crowds on Demand was founded in October 2012 by Adam Swart. Swart says the idea came to him when, upon disembarking from an aircraft on a trip to Estonia, he wished for a crowd to cheer for him.