Impulso.
Counting starts with the gun at 5:50am Saturday and everyone begins on zero. Most steps from there to Sunday night wins, with a $1,000 pool shared across the top three.
Free to download. No subscription, no entry fee.
You don't need a bib. The Stromlo Challenge is open to everyone, so you can take part from wherever you are.
Fair warning though. A half marathon is around 27,000 steps before anyone has even left the event, so the runners are going to be very hard to beat.
Stromlo is a one off, but Impulso runs comps all year. One day comps every Monday, Wednesday and Friday. Last One Walking, where missing the daily step target knocks you out and the target keeps climbing. And Hot Potato, where you grab a mate and whichever team falls behind is holding the bomb. All free to join.