A private, offline-first iPhone log for adults on a clinician-prescribed self-injection protocol. No account. No server. No third-party SDKs. Built by a practicing physician who got tired of patients showing up with broken spreadsheets.
A real, fully-refundable pre-order — the honest way to learn whether this is worth building.
Marker records what you do and what your bloodwork says, charts it as plain trend lines over time, and hands you a one-tap PDF for your appointment. It does not interpret, score, predict, or judge your numbers — that is your clinician's job, not an app's. Everything lives on your iPhone and nowhere else.
Most apps in this space want to be your advisor. They paint your labs red and green. They draw an "estimated level" curve between your data points. They bolt on AI that tells you what your numbers "mean" and what to do next. We looked hard at all of it and chose to ship none of it.
No reference ranges, no high/low, no good/bad coloring. A number on a chart is just a number you and your clinician read together. The moment an app colors it, the app is making a clinical claim it isn't qualified to make.
No estimated-level or PK curves. We will not draw a line your blood didn't actually measure. The only dots on your chart are the values you entered, on the days you entered them.
No AI "insights." Nothing in Marker guesses, summarizes, or nudges. Your data is not training fuel and not a conversation with a model. It is your record, charted honestly.
No dose calculator. We log the dose you and your clinician decided on. We don't suggest one.
We could have shipped every one of these features. They demo well and they sell. We left them out because a log you can fully trust is worth more than an app that quietly tries to be your doctor. The restraint is the product.
Log a dose straight from a Home Screen widget — no app-open required.
Mark where each shot went and see your rotation at a glance.
Enter your own values and watch them as plain lines over time — zero good/bad coloring.
Note how you feel alongside your logged doses, so the context is yours to read.
Gentle nudges for your next dose and your next blood draw.
A clean, on-device summary to hand your clinician. No emailing your health data to a server to make it.
No account, no password, no cloud. The app works in airplane mode.
Zero third-party SDKs and an honest "Data Not Collected" label — because there's nothing to collect.
Tap the widget when you inject, mark the site, jot a symptom note — seconds, not a spreadsheet.
Type in your own values after each draw. Marker charts them as neutral trend lines.
Tap once to generate an on-device PDF and walk in with your full picture instead of a shrug.
We're validating before we write the app, and the only signal that counts is whether people will actually pay — not collect emails. Reserving the lifetime license is a real, refundable charge. That's the point. If we don't ship, you get every cent back.
A practicing physician who got tired of patients tracking a prescribed protocol in spreadsheets and notes apps that fall apart, then showing up to appointments with nothing useful to share. We keep the founder pseudonymous on purpose: no personal identity attached, and therefore no temptation to dress this up as personalized medical advice. You are not buying a guru. You are buying a clean, neutral log built by someone who has sat on the other side of the appointment.
No, and that is deliberate. Marker never labels a value high, low, normal, good, or bad, never draws an estimated-level curve, and never offers AI interpretation. It charts the numbers you enter, exactly as you enter them. What they mean is a conversation for you and your prescribing clinician.
Fully on-device. No account, no login, no server, and no third-party SDKs — so there is no analytics vendor quietly collecting "usage data" in the background. The App Store privacy label reads Data Not Collected because that is literally true. The app runs with no network connection at all.
Your data is yours to protect. Marker supports an encrypted backup that you control and restore to a new iPhone — the backup is encrypted and never passes through our servers, because we don't run any. We can't read it, lose it, or hand it over, because we never have it. (Standard iPhone device encryption protects the live data too.)
Most of them collect some usage analytics, and many add AI summaries, dose calculators, and estimated-concentration curves. Marker provably collects nothing and deliberately ships none of those interpretive features. The wedge is restraint plus a clinician-built design and a real one-tap doctor PDF — a tool that logs honestly instead of trying to advise you.
None. This is a pre-launch validation, not a shipped product. You're reserving a lifetime license at $49.99 today; you can request a full refund at any point before launch, no questions asked. If we decide not to build, we refund every Founding Member automatically.
We'll email you once when it ships — nothing else, ever. No charge today.