One·Two is a free interval timer PWA for any workout format: HIIT, tabata, strength, cardio. What makes it different: • No ads, no registration, no account needed • Works fully offline after the first visit • Custom music tracks for work and rest phases separately • All data stays on your device — nothing sent to servers • Installs as an app on any phone without an app store Simple idea: One = work, Two = rest. Set your intervals, add music, train.