April, who opted out of the final year of his contract with the Bills, agreed to a three-year deal. The Pittsburgh Steelers, along with several other teams, had expressed interest in him.
April decided to take the Eagles' offer after coach Andy Reid convinced him that he wanted to make a major commitment to a talented group of special teams players, including wide receiver DeSean Jackson, who made the Pro Bowl as a receiver and a returner.
April is considered one of the league's top special teams coaches and has won several coaching awards. This was the first major move by the Eagles this offseason.
Daisher spent last season with the Eagles after coaching with the Cleveland Browns.
The Eagles also fired strength and conditioning coach Mike Wolf and assistant strength and conditioning coach Jay Merlino.
John Clayton is a senior writer for ESPN.com. Information from The Associated Press was used in this report.