The company makes , a wireless bridge device that lets the iPhone double as a heart monitor and fitness tracking system. The 3.5-by-1.5-by-0.5-inch, 3-ounce SMHeart Link collects data from several different sensors--heart rate monitors, cycling sensors, and so forth--sending what it collects to the iPhone or iPod touch via Wi-Fi. When you're done with a workout, just upload the data with a touch of a button to any of the apps that have been developed to work with the SMHeart Link.

"There's a ton of fitness apps [on the App Store]," iTMP founder and CEO Michael Williams told me last month at Macworld Expo where he was demoing SMHeart Link and its attendant apps on a stationary bike. "But none listen to your heart."

Williams knows first-hand the importance of an impactful workout regime. A few years ago, he says, he was on a number of medications for obesity-related illnesses. After committing to a workout program--which included tracking his blood pressure, weight, and resting pulse on an Excel spreadsheet on his Mac--he took off nearly 50 pounds. And he saw an opportunity to develop a fitness application that relied on external sensors to monitor the heart along with other workout data. The arrival of the iPhone--and the ability to develop apps for it--provided the chance to seize that opportunity.

iRPM+While iTMP has developed the wireless bridge, it's teamed up with and to provide the ability to upload data logged by SMHeart Link. There are also three apps now available on the App Store that work with SMHeart Link to monitor heart data through the iPhone; they include:

iRPM+ , a bike computer and heart rate monitor that uploads information from completed workouts to the New Leaf or MapMyFitness sites;