C2K is a free, open-source running trainer for Android that guides you from the couch to running 5K or 10K — with no Google services, no tracking, and no ads. Features: • Couch to 5K (C25K) — 9-week program, 3 runs per week • Couch to 10K (C210K) — 14-week program • Audible voice prompts — "Start running", "Walk for 90 seconds", countdown warnings • Background workout timer — continues with screen off • GPS tracking (optional) — records distance and pace; works without GPS too • Progress tracking — remembers which weeks and days you've completed • Works offline — no internet permission required • No Google Play Services required — compatible with GrapheneOS and de-Googled devices Permissions: • FOREGROUND_SERVICE — keeps the workout timer running with screen off • WAKE_LOCK — prevents the CPU sleeping mid-workout • ACCESS_FINE_LOCATION — optional GPS for distance/pace tracking (you can skip this) • POST_NOTIFICATIONS — workout notification with pause/stop controls C2K is free software released under the GNU General Public License v3.