The app that tracks your blood biomarkers and fitness-tracker data together

Your ferritin came back at 38 ng/mL. It’s sitting in a PDF inside your lab’s app, flagged green, inside the normal band, filed under fine. Two icons over, your ring’s app shows resting heart rate up 7 bpm this month and HRV sliding for three weeks straight. Both true, both on your phone, and nothing on either screen knows the other number exists. You’re the integration layer. You’re doing the join in your head, from memory, badly.

That’s the gap the search “an app that tracks blood biomarkers and fitness-tracker data” actually names. You bought the blood-biomarker panel. You bought the fitness tracker. What you don’t have is the one thing that would make them worth more together than apart: something reading them on the same screen, against the same clock. A dashboard that parks two feeds side by side and calls it integration won’t do it.

Why most apps track one and silo the other

Lab apps are built around the draw. A vial goes to a machine, a result comes back, it gets a reference range and a flag, and the app’s job ends there. The portal your hospital gave you is a filing cabinet for PDFs. It has never heard of your ring and was never meant to.

Wearable apps are built around the device. Oura, Apple Health, Whoop: steps, sleep stages, HRV, a readiness score every morning. They are very good at the thing strapped to your body and have no idea what your ApoB or HbA1c is. There’s no field for it.

The split is structural, not lazy. A continuous glucose monitor takes a reading about every five minutes; a blood draw is one timestamp a quarter. Those are different shapes of data, from different companies, sold on different business models. Nobody set out to silo your health. The architecture did it for them, and you’re left holding two half-pictures.

The honest steelman is the all-in-one health apps that do import both. Some let you upload a lab PDF and sync your ring. Useful, and a real step up. But open most of them and you find a blood tab and a wearable tab. You swipe between them. Importing two datasets into one app is not the same as reading them together. The numbers share a login, not a thought.

What an app that tracks blood biomarkers and fitness-tracker data should do

Four things, in order. Each is a verb the software has to perform, not a feature it can list.

One timeline. Every lab marker and every wearable stream on a single clock, so the week a number moved you can see what else was true that week. This is the load-bearing idea, and it’s worth its own read: putting labs and wearables on one timeline is what turns two archives into one record. Without it, the other three are impossible.

Cross-referenced. It puts two signals next to each other and says something neither could say alone. Ferritin 38, plus that 7 bpm rise in resting heart rate, plus three weeks of thin deep sleep, reads as low iron dragging your recovery. Read in separate apps, the same three facts read as “normal ferritin,” “bad sleep,” “unrelated,” and you change nothing.

Trend-aware. It grades the slope, not the dot. An hs-CRP of 1.1, then 2.0, then 3.1 mg/L across three draws is a finding, even though the first two clear every lab flag and the third only just crosses the 3.0 risk line. An app that re-flags each value against the population band and forgets the last one will wave that whole climb through.

Interpreted. It tells you the one thing to change before your next draw. And when it hasn’t seen enough of your data, it says “not yet” instead of guessing. Charting four feeds in pretty colors and wishing you luck is not interpretation. The work is the sentence at the end, not the graph.

How Depth reads bloodwork and wearables as one

This is the product we built, so here’s exactly what goes in. On the panel side: ApoB, Lp(a), fasting insulin, hs-CRP, HbA1c, ferritin. On the wearable side: HRV, resting heart rate, VO2 max, sleep stages, and CGM glucose, pulled from Oura, Apple Watch, Whoop, and a continuous glucose monitor. Same timeline, same screen.

The blood half is the half a wearable can’t reach on its own, so Depth closes it directly. At-home phlebotomy across India means a phlebotomist comes to you, draws the panel, and the marker lands on the same timeline as your ring, instead of in a portal you open twice a year. The draw stops being a separate errand and becomes another point on the line.

Here’s what reading them together buys you. Your CGM shows lunch spiking your glucose 64 mg/dL, day after day, while your last two HbA1c draws crept up. The wearable alone says “rough afternoons.” The HbA1c alone says “drifting, watch it.” Put them on one clock and the overlap points to the meal, not the workload. Move the rice off lunch, and you have one thing to change and a next draw to check it against.

That overlap is what the Depth Score compresses: blood, trend, and wearables read as one number you can open up and audit, down to the markers and the slopes that moved it. One read, with its work shown.

What to look for before you pick an app

You’re close to a decision, so here’s the checklist, not a recap. Hold any app you’re weighing against five questions:

1. Does it ingest both your labs and your wearable, not one and a screenshot of the other?
2. Does it put them on one timeline?
3. Does it cross-reference them, or just let you tab between two screens?
4. Does it grade the trend, or re-flag each value as if the last one never happened?
5. Does it tell you what to do, and admit what it can’t see yet?

A “no” on three or four of these is a dashboard, not an analyst.

And one last thing the silo hides. Two apps, each showing a tidy column of in-range numbers, can both be right and still miss the only thing that matters: your personal slope, already bending, while every value stays inside a band drawn for a crowd. Reference ranges flag the tails of a population, not your baseline. The app worth paying for grades you against your own line, not everyone else’s.

That’s the read we built Depth to give. Early access and the Founders Edition are at /waitlist when you want your labs and your wearable finally reading from the same page.