A few months ago, I wanted a better way to track my weight.

I tried a number of apps, but I kept running into the same tradeoff: apps that were simple but didn't help me understand my data, or apps packed with engagement features designed to keep me coming back.

I wanted something less distracting that could help me answer the questions I actually cared about:

• Am I making progress?

• Is today's number meaningful, or just normal day-to-day fluctuation?

• When will I reach my goal?

When I couldn't find what I was looking for, I decided to build it myself.

Steady Scale is a weight tracker designed around understanding rather than engagement. It uses trends and forecasts to help you interpret your weight over time, explains what each number means in plain language, and includes educational and support resources for people who want to learn more.

A few principles that guided the design:

• Privacy first: no accounts, no servers, no ads. Your data stays on your device with optional iCloud backup.

• Simple by design: no unnecessary complexity or distractions.

• Body-neutral language, no motivational hype.

One part of the app I put a lot of effort into was the trend model. Rather than relying on a simple moving average, I tested a number of models with both real and simulated data before settling on the one with the least bias that still reacts to real changes. The resulting trend gives you a clear picture of where you are today. It also anchors the app's forecasts, which work on two time horizons: a weekly target that shows whether you're ahead of or behind your current plan, and a longer projection showing when you're likely to reach your goal.

I'm a solo developer, and this is my first app. The project drew on my background in physics and my wife's background in kinesiology, with her feedback helping shape many of the decisions along the way.

Steady Scale is available on the App Store for iPhone. It's subscription-based ($1.99/month or $14.99/year) with a 7-day free trial.

I'd love to hear what people think. If you track your weight, what works well in your current app, and what do you wish it did better?