FOSS · Free

c2k

A free Couch-to-5K/10K running trainer, fully offline, no Google services required

Available on: Android · iOS

F-Droid Google Play App Store Android Source iOS Source

c2k is a free, open-source running trainer for Android and iOS. It guides you from the couch to running 5K, 10K, and beyond — with no ads and no tracking.

Android releases are available from F-Droid and Google Play. The iOS 17+ version is available from the App Store.

Screenshots

iOS

c2k workout timer showing a five-minute warmup and the next running interval on iOS — Follow clear interval prompts

c2k program list with Couch to 5K, Couch to 10K, and other running plans on iOS — Choose a training plan

c2k completed workout summary on iOS — Complete each workout

c2k program schedule and workout preview on iOS — Preview every interval

c2k workout history and running progress on iOS — Review your progress

c2k running guide on iOS — Learn with the running guide

c2k coaching and workout settings on iOS — Customize your coaching

Android

c2k program list with Couch to 5K, Couch to 10K, and other running plans — Choose a training plan

c2k workout interval preview on Android — Preview every interval

c2k workout timer showing a five-minute warmup and the next running interval — Follow clear interval prompts

c2k workout history and running progress — Keep your progress on-device

c2k running guide on Android — Learn with the running guide

c2k coaching and workout settings on Android — Customize your coaching

Programs

Pre-C25K — 3-week gentle starter for absolute beginners
Couch to 5K (C25K) — 9-week program, 3 runs per week
Bridge to 10K (B210K) — 6-week bridge for C25K graduates
Couch to 10K (C210K) — 14-week program, continues from C25K
One Hour Runner — 13-week progression from 30 to 60 minutes continuous running
5K Improver — 8-week speed and stamina program for runners who can already complete 5K

Android features

Audible voice prompts — "Start running", "Walk for 90 seconds", countdown warnings
Customizable coaching — adjust voice speed/volume, countdown warning timing, and mid-interval cues
Vibration cues as an alternative or addition to voice
Background workout timer — continues with the screen off
Optional GPS tracking — records distance and pace; works without GPS too
Treadmill mode — indoor runs without GPS
Workout history — session log with total distance, time, best pace, longest run, and calorie estimates
Progress tracking — remembers which weeks and days you've completed
Available in 7 languages — English, German, Spanish, French, Galician, Portuguese (Brazil), Russian
Works offline — no internet permission required
No proprietary services required — compatible with GrapheneOS and privacy-focused devices

iOS features

The native Swift and SwiftUI version includes all six training programs, voice coaching, optional GPS distance and pace, background audio, and workout history with streak tracking. It requires iOS 17 or later.

c2k is free software released under the GNU General Public License v3.

Support

c2k is free, with no ads or tracking. If it's useful to you, you can sponsor its development on GitHub.

Feedback and privacy

Feedback, bug reports, and suggestions are welcome through the contact form or the source repositories. Privacy policy: iOS · Android.

c2k