Inside LifeSigns
MOSAIC: an engine built to tell you the truth.
Multi-modal Offline Statistical Analytics & Insights Correlator
Every insight in LifeSigns comes from an analytics engine we built from scratch, called MOSAIC. It reads the story of your days — sleep, movement, places, weather, music — and hunts for the patterns that actually matter. Here's how it works, in plain language.
The detectors
About 350 tiny analysts, each with one job.
MOSAIC isn't one big algorithm guessing at your life. It's a team of about 350 small, specialized pattern detectors, each watching for one specific thing: does coffee after 3 PM cut into your deep sleep? Do days with a morning walk end in earlier bedtimes? Does travel throw your heart rate off for a day or two?
Each detector only speaks up about the one question it studies — which is why LifeSigns insights are specific enough to act on, not horoscopes.
Every tile is a detector. The dim ones? Benched for underperforming.
The standard
Every claim has to earn its place.
Finding patterns is easy. Refusing to be fooled by them is the hard part. Three rules keep MOSAIC honest:
Luck doesn't count
Check a few hundred patterns and a handful will look real by pure coincidence — statisticians call it the multiple comparisons problem. MOSAIC expects this and raises its evidence bar accordingly, so lucky flukes don't make the cut.
Confidence that means something
When MOSAIC is 70% sure, it should be right about 7 times out of 10 — and we check. Its confidence is tested against held-back stretches of your own history, a practice called calibration. If the numbers drift, they get corrected.
Detectors get benched
Every detector's calls are scored against what actually happened next — continuous backtesting. Detectors whose track record doesn't hold up are pulled from your feed. The app literally benches its own analysts.
The learning
It learns your normal, not the average human's.
Alongside the detectors, a small neural network runs privately on your iPhone and learns what an ordinary day looks like — for you. Your sleep on a Tuesday, your heart after a hard workout, your rhythm when you travel. Once it knows your normal, it can flag the days that quietly break the pattern.
The same goes for forecasting. MOSAIC can learn to anticipate things like tomorrow's energy — but it refuses to show you a forecast until it has proven, on your own history, that it beats simply guessing. Most apps ship the crystal ball first. Ours has to earn it.
Even your places learn this way. Correct “location #47” to “the gym” once, and MOSAIC folds that correction into everything else it knows about your days.
The road ahead
Where we're taking it.
MOSAIC is built like an engine on purpose: everything it learns comes from streams of your daily life, so every new stream makes it smarter. The direction from here — more sources feeding the same engine, deeper adaptation to each individual person, and richer answers to the question every health app should be asking: what actually works for you?
One thing will not change: all of it runs on your iPhone. Every detector, every model, every forecast — computed on your device, never on a server.
Want honest insights about your life?
LifeSigns is in private beta on iOS, heading to TestFlight.
Get early access