A different organ fills with water every day.

Hydrabit is a simple water tracker for iPhone and Apple Watch. You log a glass in a tap, see your day at a glance, set a daily goal you choose, get reminders that stop once you hit it, and keep a streak.

Hydrabit is free to use: unlimited logging, your own daily goal, reminders, your full history, reports, trends and Apple Health sync. Hydrabit Essential adds widgets, Siri and Shortcuts quick logging, guided challenges, editing or undoing logged drinks and the Apple Watch week chart, streak page and complication. Essential is $2.99 a year with a 7-day free trial, or $9.99 once for life. Prices are in US dollars and vary by country.

Yes. Choose Water, Coffee, Tea, Juice, Soda or Other before you log. Water counts in full; the other drinks count toward your goal at a slightly lower typical value, so a coffee helps but is not scored like a glass of water.

Yes. The Apple Watch app shows today's ring and logs a glass with one tap. The week chart, streak page and a watch-face complication come with Hydrabit Essential.

It keeps the app free of ads and trackers, and it is $2.99 a year with the first week free, or $9.99 once for life.

No. There is no sign-up, and Hydrabit has no servers: nothing is sent to us.

Yes. Your drinks, goal and history stay on your device, and in your own iCloud only if you turn on the optional backup. Hydrabit has no analytics, no advertising and no third-party SDKs, and it never sells or shares your data.

Yes, both ways. Drinks are saved as dietary water, and water logged elsewhere counts toward your target.

Each day a different organ, such as your heart, brain or lungs, fills with water as you drink, on Today, on the Apple Watch and in the organ widget. It is a reminder that water is what keeps them working.

Yes. Turn on iCloud backup in Profile and Hydrabit keeps a copy of your drinks in your own iCloud, so you can restore them on a new phone. It is optional and off until you turn it on.

You can choose from 27 languages in Profile, including Arabic, Hebrew, Persian and Urdu (the app turns right to left for those), Tamil, Hindi, Spanish, French, German, Japanese and more. Tips and challenge text is still in English.

Yes, with Hydrabit Essential. Say "Hey Siri, log 350 ml of water in Hydrabit", or a glass, a bottle, a cup of tea. You can also ask how much you have had, how much is left, or your streak, undo the last drink, or open a page. The same actions are in the Shortcuts app for automations. Siri phrases are in English for now.

Settings > your name > Subscriptions, or tap Manage in Hydrabit.