As a startup leveraging wearable tech to improve health, we’re always on the lookout for others who share our mission and outlook. The author David Kerrigan is one of those people, as he illustrates with his new book, “Your Phone Can Save Your Life: How You Can Benefit from the Biggest Revolution in the History of Medicine.” In it he takes an an overarching view of the many ways in which your ever-present mobile phone can help you stay on top of your health.

Check out the book on Amazon, and read below for an excerpt from the author.


Most people know that overexposure to sunlight can have damaging short term and long term impacts on skin. Yet, as with so many other health related topics, people are often slow to take action in the absence of a clear and present danger. From sunburn, to wrinkles and even skin cancer, our body’s protective layer, which has an area of up to 2 square meters, can face quite an onslaught from the invisible power of the sun and its ultraviolet rays. There are 3.5 million cases of skin cancer in the United States each year, yet fewer than one third of people use sunscreen regularly, according to a report released by the Centers for Disease Control and Prevention.

Monitoring your sun exposure requires understanding of both UV-A and UV-B - the two types of UV radiation from the Sun that reach us through the Ozone layer (which absorbs most of the UV-B shorter wave-length rays). It is important to point out that sunlight has important positive physical effects when absorbed in moderation: UV-B induces production of vitamin D in the skin and exposure to light is increasingly seen as important in positively influencing mood. Sunshine is essential as a natural source of vitamin D. It promotes bone health, prevents many chronic diseases and synchronizes the hormonal rhythms of our body.

A common refrain from people who don’t actively protect their skin from sun exposure is that they didn’t think they were getting enough exposure for it to be a problem. And in fairness, the variability of the sun’s intensity can make managing your risk slightly tricky. It’s also significant to note that different skin types respond differently to sun. The most common classification of Skin types is the Fitzpatrick Scale, developed by a Harvard dermatologist, which assigns one of six ratings based on reaction to UV light. This scale is frequently used in apps to offer skin-type specific guidance.

Sun exposure is an area where technology may offer convenient information and accessible, timely advice. The SunSprite clip-on sun monitor measures the wearer’s sunlight and UV exposure so as to ensure exposure to enough, but not too much, sunlight. Bluetooth connects it to a nearby smartphone but it provides on-device information via 10 LEDs which signify progress towards the recommended light exposure, with the lights flashing excitedly once you’ve reached 100%. The app provides historic information on both the light exposure (in LUX) and the UV levels. One outstanding feature of the SunSprite is that it is completely solar-powered. So unlike every other device here, I’ve never had to plug it in to charge. For that reason alone, it’s one of the easiest to use devices out there.

The SunSprite focuses on the positives of sunlight alongside the risks from over-exposure. The literature accompanying the app emphasizes the scientific studies over the last 30 years that point to light therapy as an effective treatment (vs medication) for depression as well as further research pointing to potential bright light benefits for a wide range of medical conditions including insomnia, ADHD, Parkinson’s disease, and dementia.