Steve Jobs- he iconic Apple phone was born out of a grudge Steve Jobs had against a Microsoft executive.
Scott Forstall, the person who led the development of the iOS system under Jobs, revealed the story that few knew. “It all started because Steve hated this guy from Microsoft. Every time they met he always came back very angry.
Later, when Apple decided they would make a phone, they turned to the tablet prototype technology and instructed engineers to use it to create a screen the size of a phone.
Then it was sent to design and seeing the result, the co-founder of Apple decided to put the tablet (which would be the iPad) on hold, and said "we are going to develop a phone".