Privacy Policy

The short version

• No account. We do not ask for your name, email address or phone number.
• Teeth photos are used only to give you brushing tips. They are analysed and immediately discarded. We never store them.
• No ads, no analytics or tracking tools, no data sold or shared for marketing.
• You can delete everything, on your phone and on our server, from Settings.

What we collect

• An anonymous device ID. The app creates a random ID the first time it opens. It is not linked to your name, email, phone number, advertising ID or any hardware identifier. It only lets us keep your backup separate from other people's.
• Profiles. The nickname you give each profile (any name you like, for example "Dad" or "Mia"), an age group, and the preferences you choose (for example braces or sensitive gums).
• Brushing sessions. When each session started, how long it lasted, which zones were completed, whether it ended early, and how your gums felt if you answered.
• Teeth-check results. If you use the teeth check, the result we send back (zone ratings, short coaching notes and a summary) is saved so you can see your progress.

Profiles, sessions and teeth-check results are stored in a Cloudflare D1 database so your history is backed up. Rewards, streaks and settings stay on your phone.

Teeth photos

When you run a teeth check, the photos are sent over an encrypted connection to our server, which passes them to our AI provider (Cloudflare Workers AI) to look for plaque, stains and food bits. The photos are processed in memory and discarded as soon as the analysis finishes. They are never written to disk, never kept in a database, never logged, and cannot be fetched back. Your phone keeps its own copies, which you control and can delete in Settings.

What we do not collect

• No location, contacts, microphone recordings or advertising ID.
• No analytics, crash-reporting or advertising SDKs in the app.
• No push-notification server. Brushing reminders are local notifications scheduled on your phone.

Permissions

• Camera or photos: only when you choose to take or pick teeth photos.
• Notifications: only for the brushing reminders you turn on.
• Vibration: for gentle haptic feedback while you brush.

How we use data

Only to run the app: to show your brushing history, to back it up, and to produce teeth-check coaching. We do not sell your data, use it for advertising or profiling, or share it with anyone except the infrastructure provider that runs the service (Cloudflare, which hosts the app's server, database and AI). See Cloudflare's privacy policy.

Children

NxtBrush is designed for families and for children brushing with a parent or carer. Parents set up and supervise profiles. The reward settings are behind a simple parent check. We collect no personal details about children beyond a nickname chosen by the parent, an age group and brushing activity, and we show no ads.

Keeping and deleting your data

Data is kept until you delete it. In the app, open Settings → Delete everything to erase all profiles, sessions, results and settings from your phone and to delete your data from our server, including the anonymous device ID. Uninstalling the app removes local data but not the server copy, so please use Delete everything first. If you no longer have the app, write to us and we will help.

Security

All traffic uses HTTPS. Every request is scoped to your anonymous device ID, so one device cannot read another's data.

Not medical advice

NxtBrush gives brushing coaching, not a diagnosis, and is not a medical device. See a dentist every 6 to 12 months, or sooner if gums bleed for more than 2 weeks, a tooth hurts, or something looks different.

Changes and contact

If we change this policy we will update the date above, and the app will tell you about any material change. Questions or requests, including under India's Digital Personal Data Protection Act, 2023: support@nxtduo.com. We reply within 30 days.