HIIT Interval Timer | Cero vs Multi

Build an interval workout around the way you train. Cero is a flexible interval timer for HIIT, Tabata, circuit training, WODs and HYROX preparation. Set up a quick work/rest timer or program each interval in detail. Distinct colors, large controls and reliable cues keep you focused on the session instead of the clock. BUILD YOUR SESSION • Set work, recovery, sets, warm-up and cool-down. • Create advanced workouts with custom intervals, colors, icons and intensity levels. • Save, duplicate and reorder timers. • Share timers by file or QR code. • Review completed sessions in workout history. STAY IN THE WORKOUT • Follow compatible sessions with Live Activities and Dynamic Island. • Start saved or recent timers from Home Screen widgets. • Use Siri and Shortcuts to start, pause, resume and stop a timer. • Put Gym Display on a larger screen or mirrored TV. • Choose a default song or assign music to individual intervals. • Customize sounds, voice cues, vibrations and background alerts. TRAIN BY HEART RATE Adaptive HR can extend recovery until you reach your target heart rate, then guide hard efforts with low and high alerts. Pair a Bluetooth heart-rate monitor with iPhone or train with heart-rate data from Apple Watch. COUNTDOWN AND STOPWATCH The built-in countdown and lap stopwatch cover warm-ups, station changes, rest periods and race-day practice. Stopwatch sessions continue after you close and reopen the app. ON APPLE WATCH Run saved workouts from your wrist, follow heart rate and use the standalone countdown and stopwatch. Cero can save completed workouts and estimated calories to Apple Health. Automatic iCloud backups help protect saved timers and custom intervals. Useful for HIIT, Tabata, circuits, EMOM-style workouts, boxing rounds, strength and conditioning, indoor cycling, running intervals and hybrid race preparation. Feedback and suggestions: hi@flawless.studio Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

All basic features are available for free! Perfect for coaches, athletes, and anyone who needs to measure multiple times simultaneously! As a runner myself, I created this app from the perspective of athletes and team managers who want precise and flexible timing tools. A multi stopwatch and interval timer for team managers, race timing, training, games, business time tracking, and anyone who needs to time multiple people or events at once. Built for track & field, swimming, cycling, motorsport, fitness training, games, work-from-home billing, and everyday timing. Record lap and split times, manage multiple stopwatches, save results, and review past sessions in the calendar. ■Stopwatch Features Run 20+ stopwatches simultaneously (device-dependent) Record lap and split times for multiple people or lanes Save and review data with a built-in calendar view Copy or export timing results for Excel and Google Sheets No-look lap timing for fast-moving races where you cannot keep watching the screen Useful for track & field, swimming, cycling, motorsport timing, games, events, and business workflows ■Video-Synced Timing (Premium Feature) Sync stopwatch time with video playback: slow motion, fast-forward, or pause Measure finishes and lap times more accurately Review sprint finishes, swimming touches, race moments, or close results frame by frame Easily record multiple athletes' lap times by pausing the video and logging times ■Interval Timer Supports up to 99 repeats and 5 customizable intervals Set sound alerts, vibration, and background operation Perfect for Tabata, HIIT, circuit training, study sessions, cooking, and daily routines ■Recommended For Track & field coaches and team managers Swimming coaches and lane timers Runners, swimmers, cyclists, and athletes PE teachers and fitness trainers Cycling, motorsport, keirin, and other race timing Games, events, billing, business tasks, and any situation that needs multiple timers How to Use Switching Modes: Swipe horizontally to toggle between Stopwatch and Timer. ■Stopwatch Tap START, STOP, LAP, or RESET as needed Save data via the bottom-left data icon -> Save -> add a title Tap the stopwatch screen to rename players or lanes View saved data: tap Data -> Calendar -> select a marked day -> choose a title and name ■Timer Add up to 5 intervals by tapping the "+" button Set repeat count by tapping the repeat icon Tap the sound icon to toggle sound or vibration Countdown begins automatically when the timer starts Reset any time with the RESET button Sound Effects: Courtesy of OtoLogic