HydraTag — Free Water Tracker App for Android
Log what you drink, get gentle reminders and build a daily habit. Tap your bottle's NFC sticker to log even faster.
Manual logging, quick add, reminders, history and units are free and need no account. Your water history stays on your phone. In Canada, Pro adds NFC features for a one-time CAD9.99 Google Play purchase, with one included sticker and separate shipping. Google Play shows the final purchase total. Requires a compatible NFC-enabled Android phone. New here? Read the first-use guide.
How It Works
Log a Drink
Open the free HydraTag app on your Android phone, pick a quick amount such as 250 ml, and tap Add. You can also type any amount, in millilitres or US fluid ounces.
Tap to Log Faster
Optional: set the amount per tap in the app and write it to an NFC sticker on the bottle you already own. After you drink, tap your NFC-enabled phone to the sticker and the app saves that amount. Requires active HydraTag Pro and a compatible NFC-enabled Android phone.
Track Progress
Watch the day fill toward your goal, review or remove drinks in History, and let reminders pause after your first drink. You log the drink; the sticker does not measure it.
Frequently Asked Questions
Is the HydraTag water tracker app free?
Yes. Manual logging, quick-add amounts, reminders, history and unit choice are free on Android and need no account. NFC tap logging and sticker setup, reading and writing require active HydraTag Pro, an optional one-time Google Play purchase, and a compatible NFC-enabled Android phone. What stays free and what Pro adds
Do I need an NFC sticker to track my water?
No. You can log every drink by hand with the quick-add buttons or by typing an amount, and that stays free. An NFC sticker is a shortcut: tap your phone to it after a drink and the app saves the amount you set up. The sticker does not measure water. NFC tap logging and sticker setup, reading and writing require an active HydraTag Pro purchase and a compatible NFC-enabled Android phone. Manual logging, quick add, reminders, history and unit choice stay free. Track water without a sticker
How does tapping the sticker log a drink?
In the app, choose the amount each tap should log and write it to the sticker once. After you drink, hold the back of your NFC-enabled Android phone against the sticker. The app saves that amount and shows a confirmation with Undo. You log the drink; the sticker does not measure it. NFC tap logging and sticker setup, reading and writing require an active HydraTag Pro purchase and a compatible NFC-enabled Android phone. Manual logging, quick add, reminders, history and unit choice stay free. Compatible third-party NFC stickers may work for Pro users, but a sticker never unlocks Pro: Pro is verified through your upgrade, not through the sticker. How sticker logging works
How do the water reminders work?
Turn on Remind me to drink water in Settings, pick three, four or six reminders a day, and allow notifications when your phone asks. Reminders can pause for the rest of the day once you log your first drink. Set up reminders
Can I use ounces instead of millilitres?
Yes. Choose Millilitres or US fl oz in Settings. Every drink is stored in millilitres and shown in the unit you pick, so switching units later does not change your history. Millilitres vs US fluid ounces
Can I correct a drink I logged by mistake?
Yes. Tap Undo right after logging, or open History, select the day and remove the entry with the cross beside it. Removal cannot be undone, so log the correct amount again if you need to. History shows 7-day, 30-day and yearly views with your goal days. Review and correct your history
Where is my water history stored?
On your phone, with no cloud sync of water history. Free manual features need no account. You can clear today or delete all history in Settings, and uninstalling the app removes its data. Pro uses Google sign-in and purchase verification; claiming the included sticker needs a delivery address. Restoring Pro does not restore water history lost after uninstalling or clearing app data. Read the privacy guide
What is HydraTag Pro, and what does it cost?
HydraTag Pro is a one-time CAD9.99 purchase as displayed by Google Play; the final amount in Google Play checkout is authoritative. One Standard or On-metal NFC sticker is included, with shipping paid separately. New Android Pro sales and included-sticker delivery are Canada only. NFC tap logging and sticker setup, reading and writing require an active HydraTag Pro purchase and a compatible NFC-enabled Android phone. Manual logging, quick add, reminders, history and unit choice stay free. Buy Pro inside HydraTag under Settings → HydraTag Pro, then request delivery in the app. Shipping costs CAD2.74 untracked or CAD16.55 Registered Mail with tracking and signature service; the full total is shown before the separate Stripe payment. Stickers are not sold separately. See the Pro offer
Standard or On-metal sticker?
Choose Standard for non-metal plastic or glass surfaces. Choose On-metal for steel or other metal bottles: its ferrite backing helps shield the NFC antenna from metal interference. On-metal describes the backing, not a decorative metallic finish. Final bottle and adhesive compatibility is being tested. Choose the right sticker
What phones are compatible?
The free app is on Google Play for Android; check the listing for availability on your device. Logging with a sticker needs an NFC-enabled phone, while manual logging needs no NFC at all. Set up or rewrite your sticker in the current app. Automatic launch and logging have been tested on a Pixel 10 running Android 16; other phone and sticker combinations may behave differently. iPhone support is not yet confirmed. Compatibility and care status
Where does the included sticker ship, and how long does it take?
Included-sticker delivery is Canada only. Shipping is paid separately: CAD2.74 for untracked Canada Post Lettermail or CAD16.55 for Registered Mail with tracking and signature service. We dispatch from the Lower Mainland in British Columbia within five business days after shipping payment is confirmed and a complete, valid Canadian address is provided. Weekends and British Columbia public holidays are excluded; carrier transit time is additional. The full shipping total is shown before the separate Stripe payment. For a missing, damaged or wrong sticker, we offer a free replacement including shipping or a refund of the shipping charge. No physical return is required. Google Play handles Pro purchase refunds. If Pro is refunded before dispatch, the sticker request is cancelled and any paid shipping charge is refunded by the merchant. Applicable consumer rights remain. Delivery and order status
How should I wash a bottle with the sticker on it?
Neither sticker version is confirmed dishwasher-safe or suitable for soaking. Keep it out of the dishwasher, do not soak it, and check that your phone still reads it after cleaning. Supplier water-resistance specifications do not establish durability under repeated bottle washing.
Get In Touch
Questions about the HydraTag app or HydraTag Pro? We'd love to hear from you!
Email: support@hydra-tag.com