Ben's Outlet / 1SaleADay has the Bowflex iConnect Fit Wireless Heart Rate Monitor Kit for iPhone, iPad, and Android for $20 - $2 off with coupon code MARCHMADNESS
+ $0 shipping = $18 shipped
. Designed to pick up heart rate signal up to 0.8 meters away, and tracks intensity levels. Comparable kits cost around $60 and up.