PaceJoy is a voice-first running coach for iPhone + Apple Watch. Tell it what you want ('an easy 5K in zone 2') and just run - it talks through your AirPods: heart-rate guidance, per-km pace briefings, a halfway callout, and an honest debrief at the finish. Decisions come from a deterministic on-device engine; AI only phrases the words. If the network drops, it keeps coaching. Free, no account, no ads. Your GPS and heart rate never leave your phone. Korean and English.
