HabitGlass — Build Habits That Stick
iOS & iPadOS App

Build habits
that actually stick

HabitGlass turns your year into a living calendar of wins. Track up to three daily habits with gorgeous visuals, science-backed milestones, and themes that make you want to open the app every day.

🏋️ Workout
🎸
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February 2025
SMTWTFS
18 streak
21 done
87% rate

Your whole year,
at a glance.

HabitGlass is a beautifully minimal habit tracker for iPhone and iPad that shows your full year as a visual calendar — every day a small colored cell, every streak a glowing trail.

Unlike apps that hide your progress behind charts and dashboards, HabitGlass puts your streak right in front of you. Green cells mean done. Grey means missed. The visual weight of your consistency becomes its own motivation.

Track up to three habits simultaneously — each with its own color, time window, and calendar. Swipe between months, tap a day to mark it done, and watch your streaks grow across the year.

  • 📅
    Full-year calendar viewAll 12 months, swipeable, with your entire history visible at once.
  • 🎨
    6 gorgeous themesDefault, Stars, Dark Lord, Cotton Candy, Sunset, and Fall Harvest — with holiday overlays.
  • 🌍
    50+ global holidaysFrom Diwali to Día de los Muertos — toggleable in Settings.
  • 🔔
    Smart time windowsSet a daily time range per habit — the app highlights which habit is active right now.
Default
Stars
Dark Lord
Cotton
Sunset
Harvest
MILESTONE CELEBRATIONS

Hit 7, 21, or 66 days and the app bursts into a full-screen confetti celebration — with optional voice announcement via Siri. Habit streaks that span month boundaries are tracked accurately so you never miss a milestone.

Six reasons it
actually works.

Every design decision in HabitGlass is backed by behavioural psychology research. Here's what the science says — and how the app delivers it.

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01 / Visibility

Don't break the chain

A full calendar of your completions makes your streak impossible to ignore. Seeing 20 green cells in a row makes you feel physical discomfort at the idea of breaking it — exactly what Jerry Seinfeld built his career on.

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02 / Neuroscience

Wire in neural pathways

Habits are physical structures in your brain. Every repetition deepens the groove. HabitGlass's milestones at 7, 21, and 66 days celebrate the real neurological inflection points where behaviour shifts from effort to instinct.

03 / Friction

One tap to mark done

The biggest predictor of habit success is how easy it is to record. HabitGlass's entire UI is optimised for the fastest possible "mark done" interaction — no login, no loading, just one tap and a satisfying chime.

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04 / Focus

Three habits, not thirty

Research on willpower shows that tracking more than three behaviours simultaneously causes rapid dropout. HabitGlass deliberately limits you to three habits — enough for real change, not so many it becomes a second job.

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05 / Ritual

Time-anchored habits stick

Implementation intentions — linking a habit to a specific time — double success rates according to meta-analysis. HabitGlass lets you set a daily time window per habit and shows a live "NOW" badge so you always know what to focus on.

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06 / Reward

Celebrate every win

Variable reward — the dopamine hit of unexpected positive feedback — keeps habits sticky. The confetti celebration, milestone overlays, and chime sounds provide immediate sensory reward every time you complete your habit.

66
Average days to form a habit
Higher success with implementation intentions
91%
Of people who track progress achieve their goals

"People who vividly describe or picture their goals to themselves are anywhere from 1.2 to 1.4 times more likely to successfully accomplish their goals."

— Murphy, 2010, Dominican University Goal Research Study

Science-backed
celebration points.

HabitGlass doesn't just track days — it celebrates the moments where neuroscience says real change happens. These aren't arbitrary numbers.

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Day 7 milestone

One Week Strong

The first week is the hardest. Neural plasticity research shows that after 7 consecutive days, your brain begins forming a dedicated habit loop. You've crossed the first real threshold — this is no longer just an intention.

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Day 21 milestone

Three Weeks In

The "21 days" concept has real roots — three weeks of consistent repetition measurably increases grey matter density in habit-related brain regions. The pathway is deepening fast. Momentum is on your side now.

Day 66 milestone

This Is Who You Are

A landmark 2010 UCL study found 66 days is the average point at which a behaviour becomes truly automatic — requiring no willpower, no decision-making. After today, this habit is part of your identity. Science says so.

Cross-month streaks work correctly

A common bug in habit trackers is that streaks reset at the month boundary. In HabitGlass, the streak engine walks backwards day-by-day through the actual calendar — so a streak that runs from January 28 to February 7 is counted perfectly as 11 days, and milestones fire at exactly the right moment.

29
30
Jan
1
2
Feb
STREAK CONTINUES ↑

Common questions

Everything you need to know before downloading.

How many habits can I track? +
HabitGlass supports up to three habits simultaneously. Each habit has its own calendar view, color, name, icon, and daily time window. You can customize all three in the Settings panel.
Does it work on iPad? +
Yes — HabitGlass is a native iOS + iPadOS app. On iPad, the calendar expands to fill the full screen with day buttons that use all the available space. Stats appear as a compact bar at the bottom so nothing is wasted.
Can I backfill days I forgot to log? +
Yes. Long-press any past day to bring up the backfill confirmation dialog. This lets you mark a day as done even if you forgot to tap it at the time. Today can also be toggled on and off freely throughout the day.
What are the milestone days? +
HabitGlass celebrates three scientifically meaningful milestones: 7 days (one week — first neural pathway formation), 21 days (three weeks — measurable grey matter change), and 66 days (the proven average for true automaticity, per UCL research). Each fires a full-screen celebration and optional Siri voice announcement.
Do streaks work across month boundaries? +
Absolutely — and this was a specific engineering focus. The streak engine walks backwards through real calendar dates day by day, so a streak that crosses from January into February (or any month boundary) is counted correctly. Milestones fire at exactly the right streak day, not at month-end.
How does the time window feature work? +
Each habit has a "from" and "to" time you set in Settings. During that window, the app automatically highlights the relevant habit tab with a "NOW" badge. The active tab auto-switches as time passes. This is based on implementation intention research — linking habits to specific times dramatically improves consistency.
What holidays are included? +
Over 50 holidays from multiple traditions: US federal and secular holidays, Christian (Easter, Christmas, Ash Wednesday), Jewish (Hanukkah, Passover, Purim), Islamic (Ramadan, Eid al-Fitr, Eid al-Adha), Hindu (Holi, Diwali, Ganesh Chaturthi), Buddhist (Vesak), Asian cultural (Lunar New Year, Tanabata, Mid-Autumn Festival), Latin American (Día de los Muertos, Cinco de Mayo), LGBTQ+ Pride Month, Earth Day, and many more. Holidays can be toggled on or off in Settings.
Is my data private? +
All data is stored locally on your device using iOS UserDefaults. Nothing is sent to any server. HabitGlass has no account, no login, no cloud sync, and no analytics. Your habit history stays entirely on your phone or iPad.
Does data persist year to year? +
HabitGlass is designed as a yearly tracker — your data is scoped to the current calendar year. At the turn of the new year, you start fresh with a clean calendar. This reinforces the "new year, fresh start" mentality that research shows increases habit commitment.
Can I turn off the sounds and celebrations? +
Yes — both the full-screen confetti celebration and the Siri voice announcement can be toggled independently in the Settings panel. If you want quiet habit tracking, turn both off and you'll get only the subtle scale animation and haptic feedback when marking a day.
What does the Time Travel feature do? +
Tapping a future day triggers a playful "Time Travel" overlay — a fun Easter egg that acknowledges you can't mark future days as done, delivered with a sense of humour rather than a boring error message.
What are the available themes? +
Six hand-crafted themes: Default (clean iOS light), Stars (black space with orange + electric blue), Dark Lord (deep black with crimson, purple, and gold), Cotton Candy (blush pinks and purples), Sunset (indigo sky with blazing hot oranges and pinks), and Fall Harvest (warm parchment with rust and forest green). Each theme has its own accent palette for habit colors.
Available Now

Start your streak
today.

Free to download. No subscription. No account. Just you and your habits.