RevLab 1.6 is live on iPhone, iPad and Mac, and it's for sale. RevLab doesn't play engine recordings. It simulates the crank, pistons, valves, combustion and exhaust flow in real time, and that one simulation drives the sound, haptics, gauges and the 3D engine. Change the cylinder count or firing order and the sound changes by itself. What's in 1.6: 21 engines, from a V-twin to a quad-turbo W16, two rotaries, three race hybrids and a four-motor EV. Manual, DCT, automatic and sequential gearboxes. A drag strip with 60 Game Center leaderboards. First three weeks: 20K+ downloads and 115 Pro purchases, with revenue verified here through App Store Connect. No servers, no running costs. Full source code (Rust core + Swift/Metal app) and a finished trailer are included. Questions welcome in the chat.