Kelvin: Cold Plunge Tracker

Kelvin is a hardware-agnostic cold plunge tracker — a guided plunge timer, a session log with history and streaks, a box breathing trainer with a water safety lock, and adaptation insights. Not a tub remote. Works with ANY cold source — ice bath, cold shower, lake, or chest-freezer tub. Kelvin owns the practice, not the tub. Master the cold — on any tub, shower, or lake. Every second in the cold, counted. WHY PLUNGERS CHOOSE KELVIN • A real timer, log and history that actually work — on Android. Breath-up rounds, a plunge countdown with a first-30s cold-shock breathing coach, and a guided warm-up. The category leader still can't log a session on Android; Kelvin is built Android-first. • Works with any cold source — no hardware, no pairing, no 2.4GHz router, no $5,000 tub. Ice bath, shower, lake, stock-tank, freezer: pick a source and start. • Safety guardrails the whole category ignores — cold-shock and afterdrop guidance, too-cold and too-long warnings, contraindication warnings, and a hard lock on breath-holds in or before water. Free, and never paywalled. • Works offline, opens instantly — local-first, no account, nothing to crash. Works at a frozen lake with no signal. A COLD PLUNGE TRACKER FOR ANY COLD SOURCE You do not need a $5,000 tub to have a cold plunge practice. Kelvin treats an ice bath, a cold shower, a lake, a stock tank and a chest freezer as the same thing: a cold source, a temperature and a duration. Pick one, start the plunge timer, and the session lands in the same log as every other. Moving from a cold shower in winter to a lake in summer does not fork your history — it stays one cold plunge tracker across everything you actually do. FREE FOREVER • The plunge timer: four ready-to-run protocols — beginner ramp, Wim-Hof-style, contrast (sauna to cold) and athletic recovery — each with breath-up, a plunge countdown with first-30s cold-shock coaching, and a guided warm-up • Log every plunge in a tap or two: water temperature, cold source (ice bath, cold shower, lake, tub) and post-plunge clarity • Streaks and a calendar heatmap: current and longest streak, total time in the cold, longest plunge, minutes this week — and your full history, never capped • Box breathing trainer: guided 4-4-4-4 rounds that only start once you confirm you are on dry land, because breath-holds near water can cause shallow-water blackout • Safety guardrails: cold-shock and afterdrop guidance, too-cold and too-long warnings, and contraindication warnings when you note a heart condition, high blood pressure or pregnancy — free, never paywalled • CSV export of every session you have logged • Large text, high contrast, reduced motion — accessibility is free • Invite a friend: you both get 30 days of Kelvin+ free KELVIN+ (OPTIONAL, 100% ON-DEVICE) • Cold-capacity curve: a weekly score that weighs how long you stayed in against how cold the water was, so you can watch your tolerance trend up • Weekly coach digest: a plain-language recap written from your own logs — streaks, time in the cold, your longest plunge, and week-over-week, 3-month and 6-month trends — closing with one sensible step for next week. No cloud, no account: your data never leaves the phone THE SEARCH TERMS WE WERE BUILT FOR Cold plunge. Cold plunge tracker. Ice bath. Ice bath tracker. Cold plunge app. Plunge timer. Ice bath timer. Cold exposure. Cold shower tracker. Box breathing timer. A cold therapy and breathwork tracker that respects the practice — on any cold source. Kelvin is not medical advice. Cold exposure carries real risks — cold shock, afterdrop, and, with breath-holds in or near water, shallow-water blackout and drowning. Consult a doctor before starting, especially with a heart condition, high blood pressure, or during pregnancy. Feedback? Email [email protected] — we read every note.