Privacy Policy

Effective date: August 8, 2026.
Last updated: August 8, 2026.

This policy describes what information MainVain (“the app,” “we,” “us”) collects, how it’s used, and who it’s shared with.

What we collect

Voice audio. When you use voice mode, your microphone audio is processed to convert your speech into text (via Apple’s on-device or server-based Speech framework, governed by Apple’s own privacy practices, not ours). We do not separately record or store raw audio ourselves.

Message content. What you type or say — and MainVain’s replies — are sent to our backend and then to OpenAI’s API in order to generate a response. This includes:

The text of your current conversation
A small set of facts MainVain has remembered about you from past conversations (for example, your name or stated preferences), and brief summaries of past sessions, used so MainVain can maintain continuity across conversations without you having to repeat yourself

A device identifier. The app generates a random identifier (not tied to your name, Apple ID, or any account) and sends it with each request to our backend. It’s used for two things: applying a rate limit that prevents a single device from making an excessive number of requests in a day, and keeping track of your free trial and subscription status so you don’t have to re-verify it on every visit. It is not used for advertising, analytics, or tracking across other apps or websites.

We do not collect your name, email address, location, contacts, photos, or any data from other apps. We do not use any data for advertising or share it with data brokers.

Purchases and subscription status

MainVain offers a free trial followed by a paid subscription, processed entirely through Apple’s In-App Purchase system (StoreKit) — we never see or handle your payment details, card number, or Apple ID directly; that information stays with Apple.

What we do receive and store, tied to your device identifier:

Whether your device is currently in its free trial, subscribed, or neither, and the relevant expiration date
A signed transaction record from Apple, used once to verify that a purchase is genuine, via Apple’s own transaction-verification service

This is used solely to determine whether the app should let you use it — nothing more.

How we use what we collect

To generate MainVain’s conversational responses and spoken replies (core app functionality)
To let MainVain remember relevant context across conversations (personalization)
To prevent abuse of the service via basic rate limiting (security / fraud prevention)
To verify your free trial or subscription status and determine whether the app should function (app functionality)

We do not use your data to train any AI model. OpenAI’s API — which powers MainVain’s responses — does not use data submitted through the API to train its models, per OpenAI’s API data usage policy.

OpenAI — receives message content (as described above) in order to generate MainVain’s responses. Governed by OpenAI’s Privacy Policy.
Cloudflare — our backend infrastructure runs on Cloudflare Workers, which relays requests between the app and OpenAI and stores the rate-limiting and subscription-status data described above. Governed by Cloudflare’s Privacy Policy.
Apple — processes all subscription payments directly through StoreKit, and we verify purchases through Apple’s own transaction-verification service. Apple’s handling of your payment information is governed by Apple’s Privacy Policy.

We do not sell your data or share it with any other third party.

How long we keep data

Voice audio: not retained by us; processed only long enough to produce a transcription.
Rate-limit counter: retained for up to one day, then automatically discarded.
Trial and subscription status: retained indefinitely, tied to your device identifier, for as long as you use the app — this is what lets us recognize a returning device without asking you to re-verify each time. There is currently no automatic expiration on this record.
Remembered facts and conversation summaries: stored locally on your device only, and persist until you delete the app.
Message content sent to OpenAI: OpenAI retains API inputs and outputs for up to 30 days for abuse-monitoring purposes, then deletes them, per their current API data usage policy.

Your choices

Deleting the app removes all locally stored data (remembered facts and conversation summaries) from your device.
You can deny microphone or speech-recognition permissions at any time in iOS Settings; MainVain requires them to function, since voice is the only way to talk with it — you can still view your conversation History without granting them.

Children’s privacy

MainVain is not directed at children under 13 (or the relevant age of consent in your region) and we do not knowingly collect data from children. If you believe a child has used the app and provided data to us, contact us using the information below and we will delete it.

Security

Message content is transmitted over encrypted connections (HTTPS/TLS). Our API credentials for underlying AI services are never included in the app itself; all requests to those services are relayed through a backend we control.

Changes to this policy

We may update this policy from time to time. Material changes will be reflected by an updated “Last updated” date above.

Contact us

Questions about this policy or your data: developer@fush.com.sg