Privacy Policy

Account information

When you register, we collect your email address and a hashed password to authenticate you. You may optionally provide a display name.

Learning data

We store the flashcard decks (BrainPods) you create or join, your study progress, spaced-repetition ratings, card maturity levels, study streaks, and session statistics. This data is essential to deliver the core functionality of the app.

AI coach (Mira)

To create your Mira coaching report, the app prepares a summary of your study history once a day: statistics such as mastery rates, ease factors, overdue counts, fail rates and streak, together with the names of your BrainPods and decks and the text of cards you are finding difficult. This summary is sent to our AI provider, OpenAI, which generates your Learning Score, insights and study plan. Mira is available to Premium subscribers.

Usage analytics

We collect anonymised events such as cards studied, sessions started, and features used. This helps us understand how people learn with Braintain and improve the product. No personally identifiable information is attached to these events.

BrainPod requests on our website

If you suggest or vote for a BrainPod on braintain.app, we store the topic, a random identifier kept in a cookie and a one-way hash of your IP address, so each person votes once. If you give your email address, we use it only to tell you when that BrainPod is published, and delete it on request.

Card reminders by email

If you ask for the next cards of a BrainPod by email on braintain.app, we store your email address, the BrainPod, a one-way hash of your IP address (to limit how many reminders one network can request) and the anonymous analytics ID of your browser, so we can tell whether the email brought you back. We send one email the next day and at most one follow-up a few days later, and nothing else. Every email has a one-click unsubscribe link. We delete the address 90 days after you sign up.

Device and technical information

We may collect your device type, operating system version, app version, and crash reports to diagnose issues and maintain stability.

Purchase information

If you subscribe to Braintain Premium, the transaction is processed by Apple App Store or Google Play. We receive only a subscription status token. Your payment details are never transmitted to or stored by Braintain.

Firebase (Google)

We use Firebase Authentication for sign-in and Cloud Firestore to store your learning data. Google's privacy policy applies to data processed by Firebase: https://policies.google.com/privacy

Google AdMob

Free-tier users may see ads served by Google AdMob. We request non-personalised ads only, which means your data is not used to build an advertising profile. You can remove ads entirely by subscribing to Braintain Premium.

OpenAI

We use OpenAI's API to generate Mira's coaching reports. OpenAI receives the study summary described in section 1 (study statistics, BrainPod and deck names, and the text of cards you find difficult) and returns the report shown in the app. OpenAI's privacy policy is available at https://openai.com/policies/privacy-policy

RevenueCat

We use RevenueCat to manage in-app subscriptions across iOS and Android. RevenueCat receives your anonymised device ID and subscription status. Their privacy policy is available at https://www.revenuecat.com/privacy

Resend

Card reminder emails are sent through Resend. Resend receives your email address and the content of the email. Their privacy policy is available at https://resend.com/legal/privacy-policy

Vercel

Our website (braintain.app) is hosted on Vercel, which may log standard web server data such as IP addresses and browser user-agent strings for security and performance purposes.