How to use the HydraTag water tracker app on Android
HydraTag is a free water tracker app for Android. This guide covers the first ten minutes: install, choose a goal, log a drink, and decide whether you want reminders or a sticker. No account is created in the current free app, and no sticker is required.
Before you start
You need an Android phone and the HydraTag app, free on Google Play. Check the listing for availability on your device. NFC is optional: it only matters if you later set up a sticker. Everything below works with the phone alone.
Step 1: the three setup screens
- Welcome. The first screen explains the three ideas: log what you drink, optionally tap a sticker, and keep your history on the device. Tap Let's get started. The note under the button says it plainly: you can use HydraTag without a sticker.
- Make it yours. Add a name if you like (optional), pick the silhouette shown on Today, choose Millilitres or US fl oz, and set a daily goal. The app starts at 2,000 ml and accepts 100 to 10,000 ml. Treat the goal as a personal target you can change any time, not a medical figure; see millilitres vs US fluid ounces.
- Quick guide. A four-point summary of logging, stickers, undo and Daily Drop. Tap Start tracking.
Step 2: log your first drink on Today
Today shows your silhouette filling toward the goal, the total so far, a percentage bar and the amount still to go. Under Quick add are three preset amounts (250, 500 and 750 ml on a new install). Pick one and tap Add. A confirmation such as "250 ml saved" appears with an Undo button, and the drink joins the Today's drinks list.
Need a different amount? Tap Choose another amount to open Log water, type any whole number from 1 to 10,000 ml (or the ounce equivalent) and tap Save drink.
| What Today shows | What it means |
|---|---|
| Silhouette and percentage | Logged total divided by your goal. It shows what you log, not a measurement of your body. |
| "… to go" or "Daily goal reached" | The difference between your goal and today's logged total. |
| Today's drinks | The three most recent drinks today; View all opens History. |
| "Tap your sticker here to log a drink." | Shown only when NFC is on and a sticker could be read. Ignore it if you have no sticker. |
Step 3: make the quick buttons match your containers
Open Settings, scroll to Quick log amounts, and change Button 1 to 3 to the sizes you actually drink from, for example a 350 ml glass, a 500 ml bottle and a 750 ml bottle. Tap Save preferences. The buttons on Today update immediately. See tracking without a sticker for more preset ideas.
Step 4 (optional): reminders
In Settings, turn on Remind me to drink water, pick a schedule and allow notifications when Android asks. Reminders can pause for the rest of the day after your first logged drink. Details and permission fixes are in the water reminders guide.
Step 5 (optional): a sticker on your bottle
The Sticker tab writes a fixed amount to a compatible NFC sticker; after that, a tap on the sticker logs that amount. In the current app version (0.1.10), NFC sticker setup and tap logging are free. In the forthcoming release, NFC tap logging and sticker setup, reading and writing will require an active HydraTag Pro upgrade; manual logging, quick add, reminders, history and unit choice stay free. One free sticker will be included with the planned HydraTag Pro upgrade, which is coming soon. How the tap works is explained in NFC sticker logging, and what stays free is in free vs Pro.
Where everything lives
- Today: progress, quick add, undo, Daily Drop card, today's drinks.
- History: 7-day, 30-day and yearly views, goal days, remove a drink.
- Sticker: amount per tap, sticker setup, read a sticker's amount.
- Settings: name, silhouette, units, goal, quick amounts, notifications, appearance (light, dark or system), data deletion, privacy policy.
Open the app at least once a week if you use reminders or Daily Drop; the app schedules them a week ahead on your phone. Your history and settings stay on the device, as described in the privacy guide.
HydraTag guide · Updated October 2, 2026