An ex-Fitbit boss just launched a $299 smart pendant to save your skin
The90, founded by former Fitbit executive Stacy Salvi, debuts the Gem UV sensor—a $299 modular pendant that measures real-time UVA/UVB exposure and delivers personalized sun protection advice.
Condensed by AI-Portable from Editorial queue.
Skin health startup The90 just crashed the wearables party with an accessory that doesn’t count steps or heartbeats—it watches the sun. The company, founded by ex-Fitbit executive Stacy Salvi, has unveiled the Gem, a $299 smart pendant designed to measure real-time UVA and UVB radiation and whisper personalized protection advice straight to your phone. It’s a deliberate departure from the wrist-based trackers Salvi helped shepherd to millions of users during her decade-plus at Fitbit and, after its $2.1 billion acquisition, Google. The Gem is jewelry first, health sensor second, targeting women who might balk at yet another screen-laden device but still want data-driven skincare.
Micro-Environment Sensing vs. Broad Estimates
Most of us check a weather app’s UV index before heading outside. That number is a blunt instrument—a forecast for a whole zip code, not your actual exposure on a partly cloudy balcony or next to a sun-blasted window. The Gem flips that model by sampling UV levels directly from the wearer’s immediate environment. Clip it to a necklace, bag, or lapel, and its onboard sensor continuously logs both UVA (aging) and UVB (burning) radiation. The companion app merges this live feed with a personal profile: skin type, protective clothing, and the details of your morning sunscreen application. The result is an adaptive routine—alerts when you’ve reached your safe sun dose, reminders to reapply, and a cumulative sun load score that evolves throughout the day.
This micro-environment approach puts the Gem in a different league than smartphone UV widgets. It also distinguishes it from earlier patch-based UV monitors (like those from L’Oréal’s La Roche-Posay and Gatorade-backed Epicore Biosystems) that didn’t offer the same always-on, accessory form factor. The pendant is modular, so users can swap the sensor puck between different necklace designs, subtly blending tech with fashion.
A Pricey Bet with Growing Precedent
At $299, the Gem lands squarely in premium wellness territory—more expensive than an Oura Ring but less than a high-end smartwatch. Salvi is clearly betting that sun protection will follow the path of sleep tracking and red light therapy: niche at first, then mainstream as the health implications become undeniable. The timing feels right. Consumer obsession with skincare has never been more intense, and the wearable market is splintering beyond step counters into rings, patches, and now pendants that measure sweat, posture, and UV load.
- UV patches from L’Oréal and La Roche-Posay pioneered the category but lacked the Gem’s real-time, cumulative tracking.
- Sweat analyzers from Gatorade and Epicore showed that single-metric body-worn sensors can find an audience.
- Smart rings like Oura proved people will pay a premium for continuous, passive health data.
The Gem’s early entry could position The90 at the forefront if—and it’s still a substantial if—UV exposure becomes a measurable vital sign for the wellness class. Salvi’s pedigree adds credibility: she knows how to launch niche hardware that eventually feels indispensable. Whether a sun-sensing pendant can make that leap depends on whether enough people decide their phone’s UV index isn’t good enough for their skin.