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FitWoody on iPhone: home screen with readiness, training load and sleep
FitWoody on Apple Watch Ultra with FitWoody complications on the watch face

FitWoody

Built for the days when you want to give up.

How a two-person team made a health app recognized by Apple. 35 languages, three devices, and one release a month.

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Active · Monthly Releases

Project fact sheet

Case study No. 01

FitWoody icon

Client

FitWoody · Chubby Studio

Sector

Health & Fitness

Period

2023 · Present

Status

Active · One release per month since 2.0

Our role

Product, brand, UI/UX design, development, and launch

Stack

Swift · SwiftUI · HealthKit · Foundation Models · WidgetKit · watchOS

Platforms

iPhone · iPad · Apple Watch

100,000

Users

35

Languages · with RTL

4.5

732 ratings · global

2

People on the team

01

Fitness apps punish you for failing.

FitWoody knows you so well that it knows how to help you keep training.

How it knows you

It reads your rest, your heart rate, your energy and the time you have today. It adjusts the day around that.

What we decided to remove

The streaks. Showing up, however you can, counts: a five-minute session is also a workout.

Ch. 02 · Design

Designed to feel inevitable.

Five decisions that are felt by using it, not found in a brand manual: how the colors speak, how the data is read, how everything moves, and what happens when you touch something.

Liquid Glass

The material is not a filter: it is the hierarchy.

The 2.0 didn't adapt the interface to the new material, it remade it with it. The glass separates what is alive from what is at rest, and that is why you never have to explain where to look.

Movement

Nothing appears: everything comes from somewhere.

Hand-timed transitions and spring physics on each ring. The movement explains where everything comes from, so the app is understood without instructions.

Color

A traffic light, not a palette.

Each color of the interface signifies a status, not a brand. In the charts, the color tells you whether to push or stop before you even have time to read the number.

In range

Elevated

Very elevated

Recovery

Core

FitWoody

Performance

In range

Elevated

Very elevated

Recovery

Core

FitWoody

Performance

Effort

A gesture, and you already know what you have just done.

You adjust the effort with one finger and, in that same gesture, the app tells you how much it adds to your load and which zone it leaves you in. The number appears while you decide.

Data analysis

A piece of data does not mean the same thing to everyone.

Before interpreting a single metric, the app asks how your week is going. Four options in plain language, not a scale from one to ten. With that, it calibrates the entire analysis.

Ch. 03 · Multi-device

One app. Three screens. The same soul.

Nobody uses the watch and the iPad for the same thing. On your wrist, you look at a piece of information for two seconds and move on; on the iPad, you sit down to make sense of your week. Each screen is designed for its moment, not just scaled up from the phone.

iPhone, iPad, and Apple Watch with FitWoody among everyday objects: sunglasses, a notebook, a coffee, and AirPods
iPhone, iPad, and Apple Watch with FitWoody among everyday objects: sunglasses, a notebook, a coffee, and AirPods

Ch. 06 · 35 languages and RTL

35 languages. Also from right to left.

Localization is not translation. In Arabic and Hebrew, the entire interface is mirrored: the navigation changes sides, the arrows flip, and every piece of data crosses the screen. The same day, read in both directions.

FitWoody on an iPhone: home screen in English with goal, workout, sleep, and metabolic metrics

English

The same FitWoody screen in the selected language; in Arabic and Hebrew, the interface is mirrored from right to left

Arabic

Arabic

Hebrew

Simplified Chinese

The 35, each in their own alphabet

Español · Deutsch · বাংলা · Català · Čeština · 简体中文 · 繁體中文 · 한국어 · Hrvatski · Dansk · Slovenčina · Euskara · Suomi · Français · Ελληνικά · עברית · हिन्दी · Magyar · Bahasa Indonesia · English · Italiano · 日本語 · Bahasa Melayu · Nederlands · Norsk bokmål · Polski · Português · Română · Русский · Svenska · ไทย · Türkçe · Українська · Tiếng Việt · العربية

Español · Deutsch · বাংলা · Català · Čeština · 简体中文 · 繁體中文 · 한국어 · Hrvatski · Dansk · Slovenčina · Euskara · Suomi · Français · Ελληνικά · עברית · हिन्दी · Magyar · Bahasa Indonesia · English · Italiano · 日本語 · Bahasa Melayu · Nederlands · Norsk bokmål · Polski · Português · Română · Русский · Svenska · ไทย · Türkçe · Українська · Tiếng Việt · العربية

Español · Deutsch · বাংলা · Català · Čeština · 简体中文 · 繁體中文 · 한국어 · Hrvatski · Dansk · Slovenčina · Euskara · Suomi · Français · Ελληνικά · עברית · हिन्दी · Magyar · Bahasa Indonesia · English · Italiano · 日本語 · Bahasa Melayu · Nederlands · Norsk bokmål · Polski · Português · Română · Русский · Svenska · ไทย · Türkçe · Українська · Tiếng Việt · العربية

Ch. 09 · Active

Nine versions in nine months.

Version 2.0 was released on October 23, 2025. Since then, not a single month has gone by without work being published, and version 3.0 is coming in September. A partner that sticks around, not one that delivers and disappears.

2.0

2.0

2.0.5

2.1

2.1

2.2

2.2

2.3

2.3

2.4

2.4

2.4.3

2.4.3

2.5

2.5

2.6

2.6

3.0

3.0

O

2025

N

D

J

2026

F

M

A

M

J

J

A

S

Version

3.0

In progress

Rebuild FitWoody from the inside out

In progress

The biggest version yet, built on everything you have told us.

Sep 2026

Version

2.6

Draw your own lines

Cycling heart rate and FTP zones defined by you.

14 Jul 2026

Version

2.5

The route was never just a line

The route shows the movement and where the difficulty changes.

29 May 2026

Version

2.4.3

Who can understand their own body?

Accessibility: understanding your health data is no longer a privilege.

6 May 2026

Version

2.4

Life does not fit into a single objective

Various goals, challenges with a target, and habits that can be reset.

15 Apr 2026

Version

2.3

Training load: the missing piece

Training load enters the equation with sleep and recovery.

19 Feb 2026

Version

2.2

Sleep, when it finally makes sense

Sleep stops being a graph and becomes a reading.

13 Jan 2026

Version

2.1

A glimpse that changes everything

The first widgets and complications for the Apple Watch.

11 Dec 2025

Version

2.0.5

Customize your units

Each with its own units: degrees, kilometers, or miles.

1 Nov 2025

Version

2.0

Built for the days when you want to give up

Rewriting from scratch, with the community already on board.

23 Oct 2025

The complete changelog, since 1.0

Ch. 08 · What they say about FitWoody

From the person who installed it yesterday to the one who opens it every morning.

We don't make products to look good in a screenshot, but for someone to keep opening them a year later. This is what the press and those who use it every day are saying.

9to5Mac logo

A fitness tracker that doesn’t punish imperfection

If you want a fitness app that understands you, instead of just spitting numbers at you, you should try FitWoody.

Portrait of Victor Abarca

Victor Abarca

@victorabarca

After seeing the progress that the FitWoody team has made over several years, I really wanted to include this app in the last video.

Ten out of ten.

Must-have app if you have an Apple Watch

Spain · @ kontrolDev

★★★★★

I've been using this app since it came out and I've been able to see the great work that the Chubby team has done and the evolution of this App.

For me, an essential one whether you have an  watch or not, they give you metrics that others don't usually provide.

Applesfera logo

When you are understood, moving forward becomes easier

The app adapts to you, not you to the app. If one day you can't, the app doesn't push you, it understands.

The application is amazing!

Russia · @Pavel_Z

★★★★★

Everything is great: the app is 100% worth every penny and unlocks the full potential of the watches to the max (300%).

Necessary complement to understand health tracking data

Spain · @aruizo

★★★★★

This application is absolutely necessary to easily understand the health parameters that our devices collect, especially for those of us who are not experts in the field. The developers are on top of it, improving it day by day and listening to users. 10 / 10

Before you ask

Do you lead the product or just execute it?

Both things, and in that order. At FitWoody, we decide what to build before building it: what deserves to exist, with which technology, and in what order. Product, brand, design, and development are handled by the same two people from start to finish.

How long does a product like this take?

FitWoody was released in 2023 and version 2.0, which was a complete rewrite, in October 2025. Since then, we have published a release every month. It is not a demo shown once: it is a living product.

Can you step into a product that already exists?

FitWoody 2.0 was exactly that: rebuilding an app that already had users, while continuing to release updates along the way. Stepping in halfway through is not the exception, it's the rule.

Do you only make health apps?

No. Health and fitness is the sector of this project, not our method. We make apps, web, and agents; the platform is defined by the project, not a fixed stack.

Who maintains it afterwards?

We do. FitWoody's changelog is public and the cadence is visible from the outside: we don't deliver and disappear.

And what if I only want the design part?

You can, but we say what we think: half of what makes FitWoody good are decisions that only hold up if the person making them is also the one building them. Tell us about the case and we'll give you our opinion before taking it on.

Hello!
Portraits of the Chubby Studio team: Patricia taking notes and Asier in front of his laptop

Are we a fit?

If you've made it this far, something must have resonated with you. Tell us what you want to build, and we'll tell you frankly if we are the right studio for you.

If you've made it this far, something must have resonated with you. Tell us what you want to build, and we'll tell you frankly if we are the right studio for you.

© 2024 CHUBBY STUDIO S.L.

Vitoria-Gasteiz (Spain)

Designed and built with ♥ and a lot of coffee by Chubby Studio.

LAST UPDATE: 22-08-26

chubby footer
© 2024 CHUBBY STUDIO S.L.

Vitoria-Gasteiz (Spain)

Designed and built with ♥ and a lot of coffee by Chubby Studio.

LAST UPDATE: 22-08-26

chubby footer
© 2024 CHUBBY STUDIO S.L.

Vitoria-Gasteiz (Spain)

Designed and built with ♥ and a lot of coffee by Chubby Studio.

LAST UPDATE: 22-08-26

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