The forward started his career at Aston Villa as an eight-year-old before moving to Nottingham Forest. He signed for Crawley Town in June 2007, scoring 22 goals in 61 appearances. In 2009 he joined Wycombe, scoring 14 goals in 77 appearances. Following an injury last year, his appearances were limited.
Manager Chris Wilder said: "JP is a very positive player who has the ability to create and score goals. He has electric pace and gives us a balance to the squad. I am delighted to have beaten off stiff competition for his signature and he is a definitely a signing that will excite the supporters."
