The planet, divided into 1.66 trillion hexagons (~307 m² each). Stand on one, tap, and it's yours permanently. The first person there keeps it forever. Attach a photo of the exact ground you claimed; a daily feed shows everyone 10 random ones. 180,000+ hexes claimed across 98 countries in under two weeks, including one man who walked 20 km and claimed 1,566 in a day. Free, browser-only, no install. Built in a few days as a side project. Now it's a race to a million.