This dynamic move tones your arms and legs while getting your heart rate up; here's a GIF demonstrating how.
Stand with your feet shoulder width apart, and extend your arms straight out to either side with palms facing down. This is the starting position.
Jump, and cross your right arm over your left and your right foot over your left. Jump back to the starting position, then cross with the opposite arm and foot. This counts as one rep.
Continue alternating sides and repeating this movement until you complete 25 reps. Be sure to keep up the pace and not allow too much time for recovery between jumps; this way you'll be sure to keep up your heart rate and engage your whole body.