Fitness tracker with an AI coach

Training, nutrition and a coach that knows your day.

Hotaru brings your workout log, food diary and routines together in one place, in a warm, calm look. The AI coach offers ideas that fit your goals and the data you logged.

Download on the App Store

Google Play: coming soon

Free to use, optional Premium subscription. A wellness app, not a medical device.

App screenshot of the daily overview: an energy ring with 1390 kcal eaten, protein, carbs, fat and fiber against daily goals, and the supplement routine.

Features

Everything for your day in one place

The home dashboard shows calories, macros, water, steps and your supplements. You see right away what is still open today.

An AI coach that listens

Ask about training, nutrition and everyday habits and get ideas that fit your goals. You decide which data the coach may see.

  • Answers based on your goals and, if you like, your training and nutrition history
  • Dictate instead of typing, attach photos
  • Clearly labelled as AI: answers can contain mistakes
App screenshot of the coach chat: asked what to eat tonight, the coach suggests salmon with potatoes and vegetables to reach the protein goal.

Nutrition, simply tracked

Log meals by search, barcode scan or as a quick entry. The diary puts everything on a timeline, and the week strip shows your calories day by day.

  • Food search and barcode scanning
  • Calories, protein, carbs, fat and water
  • Meal photo and nutrition label by AI with Premium, plus a few free meal photos per week to try
App screenshot of the food diary: week strip, daily macro totals and a timeline of meals and water.

Training with a plan

Plan your splits, log sets, weights and reps, and use the rest timer. The muscle map shows which areas you have trained this week.

  • Your own plans and a workout log
  • Stats and personal bests
  • AI training plans and progress analytics with Premium
App screenshot of the training tab: a six-week streak and a muscle map showing 84 percent of the body trained this week.

Weekly check-in

Once a week you look back: workouts, calories, protein, weight trend. If you like, your goals are adjusted to your trend.

App screenshot of the weekly check-in: the week's weight trend and progress on workouts, calories, protein and supplements against the goals.

Achievements and colour worlds

Collect badges across several ranks, discover secret achievements and give the app your own look with colour worlds.

App screenshot of achievements: badges with ranks such as gold, silver and bronze and their progress.
App screenshot of colour worlds: a preview and a selection of colour worlds such as Hotaru, Aurora and Sakura.

AI and your data

A coach with clear boundaries

Ask first, then send

Before an AI feature sends data for the first time, the app asks for your explicit consent. Without consent the AI features stay locked and everything else keeps working. You can withdraw it at any time in the app.

You set the scope

You choose in the coach settings how much the coach sees: from just your goals up to training, nutrition and body data. Health data is not used for advertising, marketing or tracking.

Apple Health, if you want

With your permission, Hotaru reads values such as steps, active energy, sleep and weight from Apple Health and writes workouts, weight and meals back. You can change access at any time in Settings.

Important: Hotaru is a wellness and fitness app, not a medical device. The app and the AI coach do not provide medical advice, diagnosis or treatment. AI answers can contain mistakes. For health questions, please talk to a doctor.

Free and Premium

Start free, go Premium only if you want to

Free

Everything for every day

  • Food diary with search and barcode scanning
  • Workout log and your own plans
  • Achievements, supplements and weight
  • A limited number of coach messages per day
  • One coach insight per week
  • A few AI meal photos per week to try
Premium (optional subscription)

More coach, more insight

  • Coach without a daily cap (fair use)
  • AI training plans and periodisation
  • Workout insights and progress analytics (1RM trend, volume per muscle group, month and year comparison)
  • Meal photo and nutrition label by AI
  • The Bio area with sleep and recovery data
  • Recommendations after check-ins and a body-fat estimate from a photo
  • All colour worlds

Prices and terms are shown in the app before you buy. The subscription is billed through your Apple Account, renews automatically and can be cancelled up to 24 hours before the end of the period in your Apple Account settings.

FAQ

Frequently asked questions

Which data goes to the AI, and how do I withdraw consent?

Only after your explicit consent, and only the data needed for the answer you asked for. It is sent through OpenRouter to the model providers (Anthropic, possibly Google), including in the USA. Photos of meals, labels and check-ins are sent once for analysis and are not stored on Hotaru's servers.

You can withdraw consent at any time in the app under Coach → Settings or Profile → Help & Support → AI consent. Details are in the privacy policy.

How do I cancel my subscription?

Apple manages subscriptions: Settings → Apple Account → Subscriptions → Hotaru. Cancel at least 24 hours before the end of the period, otherwise it renews. Deleting the app or your account does not cancel a subscription.

How do I delete my account?

In the app: Profile → Account & security → Delete account and confirm. This deletes the account and its app data. All steps and exactly what is deleted are on the Delete account page.

What happens to my health data?

Hotaru only accesses Apple Health after you allow it in iOS. You can change that under Settings → Privacy & Security → Health. Without permission, the other features remain available. Health data is not used for advertising, marketing or tracking.

Does Hotaru replace medical advice?

No. Hotaru is a wellness and fitness app, not a medical device. The app and the AI coach do not provide medical advice, diagnosis or treatment.

Is Hotaru available for Android?

An Android version is in preparation and coming to Google Play soon. Until then, Hotaru is available for iPhone on the App Store.

How do I reach support?

Email support@hotarucoach.com. Requests are normally answered within three business days. More on the support page.

Ready for your next day?

Get Hotaru for free and try the coach.

Download on the App Store

Google Play: coming soon