C24 Cardio is a focused cardio interval timer I built for structured work and rest. You set rounds, round duration, and rest, run the session, then keep training history and progress on the device. There is no account to create.
- 01
Set the session
Choose rounds, round duration, and rest between rounds. Preset values are available, along with custom settings.
- 02
Start the workout
Start Workout begins the session from the setup screen.
- 03
Train the interval
The session opens on a GO cue, then a WORK timer with the current round count.
- 04
Control the session
Sound can be turned on. Pause and Stop Workout are available during the session. Ending a session early is confirmed, and that session is not saved.
- 05
Review progress
Progress shows sessions, rounds, and training time across today, this week, this month, and all time, plus weekly activity, current streak, and records: best session, longest session, and best day.
Designed and developed as an independent mobile product.
Screens
Setup Progress 
GO 
Work 
End workout 
Specification
- C24 Cardio
- Cardio Interval Timer · Mobile App
- Rounds, round duration, rest between rounds
- Sound, pause, stop
- Sessions, rounds, training time, streak, records
- Stored on the device. No account.
- iPhone and iPad · iOS 15.0 or later
- Free on the App Store