About TrendBody

I'm Sami — the person behind TrendBody. I'm a data scientist, and I built this app to scratch my own itch: I wanted a weight tracker that told me the truth instead of reacting to every bit of daily noise.

Why I built it

Every weight app I tried treated the number on the scale as if it were my actual weight. But a daily reading is mostly noise — water, sodium, glycogen, digestion, hormones — sitting on top of a slow, real trend. Watching that noise bounce around is discouraging at best and misleading at worst.

The math to separate the signal from the noise already existed and was well understood. It just hadn't been put in a phone in an honest way. So I built it.

The expertise behind the math

I've spent more than five years working as a data scientist, turning statistical models into software that ships and gets used. I hold two graduate degrees spanning software engineering and quantitative finance, and my day-to-day work lives in statistical modeling, time-series analysis, and machine learning.

I've co-authored a publicly funded academic randomized controlled trial, and analysis I've done has been covered by national news media. I mention this not to impress you, but because when an app makes claims about your body and your energy balance, you deserve to know whether the person behind it actually understands the methods — and stands behind them.

Why it's built the way it is

Three convictions shaped every important decision in the app.

First, the trend is a Kalman filter, not a moving average — the same family of estimator used in navigation and tracking, and the kind of method my professional work is built on. It handles missed days, quietly down-weights obviously bad readings, and estimates how fast your weight is genuinely moving instead of just drawing a smoother line.

Second, it shows you its uncertainty. I take the limits of any model seriously, so TrendBody reports confidence intervals and openly documents the cases where it can be wrong, rather than projecting a false precision you can't act on.

Third, it's designed around how people actually think. Drawing on behavioral science, the app frames progress as behavior rather than identity, keeps caloric balance hidden by default, and uses calm amber and emerald instead of shaming red and green. A weight tracker should inform you, not punish you.

Independent, and why that matters

TrendBody is built and maintained by one independent developer — me. There's no investor pushing for engagement metrics, no growth team, and no business model that depends on your attention or your data.

That's why everything stays on your device: no accounts, no servers, no analytics, nothing leaves your phone. It's also why TrendBody is a one-time purchase instead of a subscription — the math doesn't expire, so neither should your access to it. I'd rather earn your trust once and keep it than rent it back to you every month.