Steve Jobs was a creator, innovator, and full-fledged cultural icon. And for the three men behind Tawkon, a Tel Aviv startup, he was also the guy who shot them down in a one-sentence e-mail.

"No Interest" was Jobs' simple response when Tawkon CEO Gil Friedlander sought an explanation for why the company's app, which measures radiation emitted from handsets during phone calls, was rejected from Apple's App Store.

That was back in March 2011, and at the time, Tawkon's app was built specifically for the iPhone. On Thursday, a little more than a year later, the company officially hit the reset button with a redesigned app built specifically for Google's Android operating system.‪

>‬"We don’t want to keep anyone from using their phones. We just want people to have as much information as possible." – Amit Lubovsky‪

‬But the app isn't the only thing that's new at Tawkon, said Amit Lubovsky, who co-founded the startup with friends Gil Friedlander and Ori Goshen in 2009.

"We went through quite a huge rebranding process of the entire company," said Lubovsky, who serves as Tawkon's marketing and business development VP. "The app, the message, the website, the market we're trying to reach, everything has been rethought – and for the better."

When Tawkon was trying to go the iOS route, the app put statistics, graphs and a big, circular gauge of radiation front and center, he said.

"The iOS app was built more for early adopters and geeks," Lubovsky told Wired. "The new app on the back end is the same. How we measure radiation is the same technology. But the front end, what the user sees, is totally different and not as geeky."

The app measures a phone's radiation levels by collecting data on what network band a phone is running on, the wireless antenna it's using, and how hard the phone has to work to get a cellular signal. All this information is exposed by the phone's OS.

Tawkon's app analyzes all this data by way of a patent-pending algorithm, and offers up a real-time calculation of the phone's radiation emission, and the rate of radiation absorption a user is facing. If the app determines radiation levels are high, it issues suggestions on how to talk more safely.

The Android version of Tawkon was built with a specific audience in mind: people who care about health and wellness. Indeed, even though a phone's radiation emissions might pass FCC muster, they might still be too high for people worried about radiation absorption risks.

"If you like the Nike+ apps, if you like Fooducate or Lark or RunKeeper, Fitbits and things like that, then we think you'll like Tawkon too," Lubovsky said. "We're still telling people how much radiation is coming from their phone, and we're still making suggestions so people can use their phone safely. But with the new product, we've simplified it dramatically and made it a lot more accessible to users."

The new app is colorful and attractive, clearly stating what a user's "exposure this week" is, and tracking whether a user was communicating via a handset, headset or speaker. The app also includes a feature that allows users to invite friends and family to use the app as well. If they do, a user can compare his or her exposure levels to others'.

Like the original iOS version of the app, the software makes suggestions on how one can reduce exposure when radiation levels are high. For example, during a call in progress, an alert can pop on screen, suggesting the use of a headset and holding the phone away from one's head.

Menus in the new app are rendered in shades of blue and orange, and users are identified with cartoon faces designed by Dutch illustation duo LouLou & Tummie. The rejected iPhone app, which was made available on the web for jailbroken iPhones, was much less elegant. It also could only track radiation after a call was made or received, Lubovsky said.

"Android is better at multitasking and allowing you to do things in the background," he said. "Our Android app can launch automatically when you make a phone call, so you don't have to go and launch an app in the middle of your phone call as you had to do in our iOS app."

So does the world really need the Tawkon app? After all, FCC regulations restrict cellphone and tablet manufacturers from building devices with excessive radiation emission. (Gadget Lab investigated this topic in December 2011.) Lubovsky says, "We don't want to keep anyone from using their phones. We just want people to have as much information as possible. That's why we chose the name Tawkon. We want people to 'talk on' and be safe while doing it."

While the radiation risks of mobile devices are still being studied, the Tawkon app's radiation measuring ability has been tested by Satimo, an FCC-certified lab that tracks radiation levels for various types of devices.

"Our resent testing results clearly confirmed Tawkon's effectiveness as an accurate tool to predict SAR levels and recommend changes to reduce users risk," Lubovsky, noting that the company commissioned Satimo to test the app out.

Going forward, Tawkon is working on adding functionality to the Android app so that it can measure radiation levels when users are doing things other than just making a call, Lubovsky said. And, eventually, the company may expand to other operating systems as well, he said.

"We had a BlackBerry app out for a bit and we're paying close attention to Windows Phone," he said. "But currently we're focusing on Android. Mobile is quite a big market and Android is the biggest OS, so we want to make sure we're building the best Android app we possibly can – and one that works well on all sorts of different Android phones, since there are so many."