halfmarble
we build iPhone and iPad apps
that work when your hands don't
Gerard Ziemski // halfmarble cofounder // platform architect
Gerard Ziemski // halfmarble cofounder // platform architect
Agentic coding tools changed what two people can ship. Not because they write it for me: because they clear the friction that used to end a session before the good part. An idea now survives long enough to become an app. So we build, for iPhone and iPad, and we use everything we ship.
There are two ways to build software for hands that shake. Design the touch so a tremor cannot spoil it: hold instead of aim, no timers, undo without limit. Or take the hands out of it altogether and use your voice. We do both.
Your heart rate, read aloud. SteadyHeartBeat speaks your live heart rate from AirPods Pro 3, with no watch, no chest strap and no glancing at a screen. Everything runs on your iPhone, and your data never leaves it.
Offline entertainment for the car, hands-free. Books, games, stories and simple conversation, all living on the phone, so it keeps working where there is no signal at all. You talk to it: no hands involved, which is exactly the point.
A casual flick-and-defend arcade game. Read the pathogen swarming your patient, arm the one cell type that counters it, and flick a homing cell to hold the line. You hold rather than aim, so a shaky finger still plays it well.
A casual color-matching puzzle game set in deep space. Steer falling strings of colored pieces, stack them, and build patterns that fuse and release their energy. No timers and unlimited undo, so nothing is lost to a bad moment.
We are a software company with one thing you can hold. SteadyHandTool is a high-stability soldering aid for fine SMD work: heavy, damped, and steady enough that small parts stay exactly where you put them. Open hardware, so anyone can build one, improve it, or make it fit their own bench.
Why the apps are built the way they are. The wearable sensing platform still in design, the Parkinson's research behind it, and the methods we publish as dated, public-domain prior art so that no one can fence them off later.
Every field we capture. Every transformation we apply. Every "we will never." Documented, public, plain language.
SEE EXACTLY WHAT GETS SHARED →
"I have Parkinson's. It is why every app here is built to work with unsteady hands, and why I know when one doesn't."
A nurse and a programmer. We built this. Just us.
halfmarble gives 5% of net profits to the organizations whose research our work stands on. Not charity in the abstract: reinvestment in the commons we build from.
Annual donations published. Committed. Non-negotiable.
Bachelor of Science, Honors Computer Science degree from Western University in 1998, plus two years toward an M.Sc. — dropped out to join Apple. Twenty-five years writing software. New Media Lab. Apple. Sun Microsystems. Oracle. Two patents along the way. Early open source contributor to gl4java and jogl — Java bindings for OpenGL — back when Java on the desktop still felt like the future.
Diagnosed with Parkinson's Disease over 10 years ago. It is why every app here is built to work with unsteady hands, and why I know when one doesn't.
Agentic coding tools brought back the part of this job I loved most. Twenty-five years in, I am shipping more, and enjoying it more, than I have in a long time.
Born in Poland. Educated in Canada. Cut my teeth in Silicon Valley. Now building halfmarble from Charlottesville, Virginia.
Off the clock: hiking, kayaking, books and games, tinkering with microcontrollers, and love for the company of dogs.
Nursing education and training in the United States. Fourteen years as a nurse. Most of them caring for geriatric patients — the population hit hardest by chronic disease, medication complexity, and the day-to-day reality of living with conditions that do not get better. Known to my employer and co-workers as a fierce patient advocate.
Born and raised in Ukraine. Volunteer as an English-to-Russian interpreter for immigration cases. Now building halfmarble from Charlottesville, Virginia.
Off the clock: cooking healthy meals for my family, hiking, and kayaking.