Phase-anchored. Cited. Quiet.
Intermittent is a free intermittent fasting tracker for Android with a phase-aware timer. Instead of counting hours, it tells you which biological phase you're currently in — Fed, Early fasting, Lipolysis, Ketosis, Autophagy, or Deep fast — and links each one to a long-form article with its primary sources cited inline.
The whole library is free, and you can read it all without making an account.
Hour by hour
Drag · or use ← →
The same rhythm strip the app shows you — six phase-coloured slabs spanning the full 72-hour arc, from Fed all the way to Deep fast. Drag the marker to any hour and watch the biology beneath it shift.
Fed
0–4h
Early
4–12h
Lipo
12–16h
Ketosis
16–24h
Autophagy
24–48h
Deep fast
48–72h
Hour 24
Cellular self-cleaning peaks
mTOR suppression drives lysosomes to recycle damaged organelles and misfolded proteins. The cell does its own housekeeping.
Fuel mix · estimate
90% fat · 10% glucose
Modeled — RER-derived. Individual metabolism varies.
On your device, today
Three screens captured straight off a Pixel running the app this afternoon. Same typeface, same accent, same dial.
Issue 01 · Timer
Not a countdown, a compass. A pill above the dial says exactly which phase you're in — "Hour 6 · Glycogen priority" — and tapping it opens the science. Below, a rhythm strip lays out the full arc of the fast, with a NOW marker drifting left to right as biology shifts.
Issue 02 · Insights
The killer chart is phase reach — how often did your fasts actually hit lipolysis, ketosis, autophagy? Most apps just show you that you fasted. Ours tells you what your body did with it. A 14-week tiered heatmap, weekly trend bars, and a time-of-day pattern back it up.
Issue 03 · Circle
Approval-gated follows. No usernames to farm. No comment field — applause is the only reply. "Fasting now" is opt-in, off by default. A circle in the real sense of the word: small, invited, quiet.
Issue 04 · Learn
Every article on this site is also in the app — phase-anchored, offline-bundled, free without an account. The article that matches the phase you're in surfaces on the Timer, one tap away from the dial.
Inside the practice
Six things that quietly do their job — none of them upsold, all of them grounded in the same primary literature the articles cite.
4–6 weeks · sex-aware
Most beginners do better easing from 12:12 to 16:8 over a few weeks than jumping in cold. The plan adapts when you're cruising or struggling, and starts with a safety screen for anyone it shouldn't be guiding.
Yamada 2022 · IOM · EFSA
A daily target that adapts to your weight, sex, age, and fast length. Built from the doubly-labeled-water literature (n=5,604) plus the IOM and EFSA convergence band — not a generic "8 glasses." Tap the card to see exactly which inputs produced the number.
Length-adapted · cited
When you end a long fast, the sheet shows length-adapted refeed guidance — gentle for an 18h, more careful for a 48h+, with refeeding-syndrome flags past 72h. The article "Breaking a long fast" cites the primary sources behind it.
12h · 16h · 24h · 48h
One persistent notification while a fast is active — a quiet companion, not a streak guilt-trip. Phase milestones fire when biology actually transitions: lipolysis at 12h, ketosis at 16h, autophagy at 24h, deep fast at 48h. Each individually toggleable.
Live phase · 60s tick
A small home-screen widget shows current phase + hours elapsed without opening the app. Tap it to start a fast or jump straight to the timer. Updates every minute via Android's AlarmManager — accurate, battery-cheap.
Export · delete · zero ads
Your data lives on the device. Sign in to back it up across devices — opt-in, never required. Full JSON export from Settings. Real account deletion that cascades through every row. No ads, no third-party trackers, no data sale, no AI training.
Six phases · six chapters
A fast passes through six biological phases as insulin falls and the body shifts fuel sources. Below: each phase, the hour range, one line of biology, and a long-form read.
Digestion & nutrient storage
Insulin shuttles glucose into muscle and liver as glycogen.
Read the science
Glycogen priority
Liver glycogen becomes the primary fuel; glucagon rises.
Read the science
Fat mobilization begins
Adipose triglycerides hydrolyze into free fatty acids.
Read the science
Mitochondrial fuel shift
Liver makes β-hydroxybutyrate; ketones cross the blood-brain barrier.
Read the science
Cellular self-cleaning peaks
mTOR suppression drives lysosomes to recycle damaged organelles.
Read the science
Growth hormone surge
GH rises 5–10×, preserving lean mass; ketones power the brain.
Read the science
From the library · sample
Mechanism · 7 min read
For most of a normal day, your cells run on glucose. You eat, insulin rises, glucose pours into muscle and liver, and anything left over gets stored — as glycogen in those tissues, or as fat in adipocytes.1 The machine hums along on sugar.
But the machine has another setting.
When you stop eating, insulin begins to fall. This is the quietest, most important switch in the whole process. Glucagon rises to counterbalance, and the liver starts breaking down its glycogen stores to keep blood glucose steady.2
The choices
Five deliberate calls we made, set against the category. Reference points below are the four most-downloaded fasting apps on the Play Store as of April 2026: Zero, Fastic, BodyFast, and Simple.
| Choice | Zero · Fastic · BodyFast · Simple | Intermittent |
|---|---|---|
| 01 Phase over time | Hours elapsed leads. A progress bar fills toward your goal; streaks reward consecutive days. | The biological phase leads — Fed, Early, Lipolysis, Ketosis, Autophagy, Deep fast. Hours are the backup read. |
| 02 Reading over ranking | Short daily tips, streak badges, weekly leaderboards, and a "Plus"/"Premium" tier paywalling anything longer. | Every article is free, long-form, sourced, and dated. Every phase on the dial links to a long read. No gated content. |
| 03 Applause over algorithm | Public stats, username search, stranger-suggestion feeds, comment sections on every post. | Approved friends only. Applause, not comments. No username search, no "people you may know". A circle in the real sense. |
| 04 Local over cloud-first | Account required to use the app. Your fasts uploaded by default. Export buried, deletion vague. | Your data lives on the device. Sync is opt-in, never required. Full JSON export from Settings. Real account deletion that cascades through every row. |
| 05 Free over freemium | Free shell, paid Premium tier behind anything useful — "advanced biomarkers", "AI coach", weekly meal plans, $79.99/year. | The whole library and the whole app are free. There is no Premium. There is no upsell screen. There is nothing gated behind a paywall. |
Common questions
Why we built this
The first time I fasted past sixteen hours, I opened the app I was using and it congratulated me with a confetti animation. It asked if I wanted to share my "achievement" on Twitter. It nudged me toward a $79.99 subscription for "advanced biomarkers", whatever those were.
I closed the app and looked up what was actually happening in my body on PubMed.
Intermittent is the app I wished I'd had that night. The dial is just the dial. The phase tells you the truth. The reading is long-form and sourced and, where the literature is contested, says so. The circle is your friends, not strangers, and there's no comment field — applause is enough.
We don't have notifications you'll regret enabling. We don't have streaks that punish you for breaking.
Just the practice and what your body is doing — and the writing to help you understand both. That's the whole pitch.
Ashish, founder · Bengaluru
Free on Android and iOS. Free library. No signup, no email field, no popup.
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