Yesterglow

Privacy Policy

Effective date: June 15, 2026

The short version

Yesterglow runs entirely on your iPhone. It connects to your own Google account, with your permission, so it can read your own email and download your own attachments straight to your device. Everything the app does after that — sorting your photos, videos, voice memos, PDFs, and other files into a memory timeline, reading text in images, recognizing scenes — happens on your phone.

We do not run any servers. We do not have user accounts. We never receive, see, store, or have any way to access your email, your attachments, your search history, or anything else from inside the app. There is no analytics, no tracking, no advertising, and no third-party software development kits (SDKs) of any kind in Yesterglow.

We say "we" and "us" to mean the developer of Yesterglow. We are the people who make the app — not a company that holds your data, because we hold none of it.

Who this policy covers

This policy describes the Yesterglow app for iPhone (bundle identifier com.wiiym.memorybox), distributed through the Apple App Store. It does not cover Google, Apple, or any other company whose services you may use alongside Yesterglow; those companies have their own privacy policies, linked below.

What Yesterglow does, and where it happens

When you connect your Gmail account, Yesterglow:

  1. Asks Google for permission using Google's standard sign-in screen, requesting read-only access to your Gmail (the gmail.readonly permission). You sign in to your own Google account; we never see your Google password.
  2. Reads your own messages and downloads your own attachments from Gmail directly to your iPhone over an encrypted (HTTPS/TLS) connection. The data flows into your device. It is never uploaded anywhere by Yesterglow.
  3. Organizes and enriches everything on your device. Yesterglow builds a private index of your memories using Apple's on-device technologies — for example, Apple's Vision framework to read text in photos (OCR) and to recognize scenes — without any network connection. None of this leaves your phone.

Because all of this processing happens locally, Yesterglow does not "collect" your data in the sense Apple and privacy laws use the term. The information stays in your hands.

The one rule that defines this app

Your email content never leaves your device. There is no Yesterglow proxy, no Yesterglow cloud, no Yesterglow backend, and no Yesterglow account. We do not send your email, attachments, message metadata, or any derived data (such as text recognized in your photos) to ourselves or to any third party. We also do not use your email data to train or improve any model, ours or anyone else's. This is the core architectural decision behind the entire app.

The only networks Yesterglow talks to

Yesterglow makes network connections to exactly two places, both on your behalf:

1. Google — your own account

To fetch your mail, the app contacts Google's own servers, using the access you granted:

  • accounts.google.com — Google's sign-in and consent screen, where you authorize access.
  • oauth2.googleapis.com — to obtain and refresh the access token that proves you authorized the app. The only things sent here are sign-in credentials (not your password) needed to maintain your authorization.
  • gmail.googleapis.com and www.googleapis.com — Google's read-only Gmail API, used to scan your message list, read your own messages, and download your own attachments to your device, plus to confirm the email address of the account you connected.

All of these are Google's services, accessed with the read-only permission you granted to reach your own mailbox. Your use of Gmail through Yesterglow is also subject to Google's Privacy Policy.

If you tap "view original message" on a memory, Yesterglow opens that message in Gmail in your browser (a mail.google.com link). That is you opening your own email at Google; it is not a background transfer of data.

2. Apple — for purchases only

If you buy Yesterglow+ or Yesterglow Forever, the purchase is handled entirely by Apple's App Store using Apple's in-app purchase system (StoreKit). Yesterglow never sees your payment details, and there is no Yesterglow server involved in the purchase. See "Purchases" below.

That is the complete list. Yesterglow does not connect to any Yesterglow-operated server (there is none), any analytics service, any crash-reporting service, any advertising network, or any other third party.

What is stored on your device, and only on your device

Everything Yesterglow keeps lives inside the app's private storage on your iPhone:

  • Your attachments (photos, videos, GIFs, voice memos, PDFs, documents, and other files) are saved in the app's private container. Duplicate files are stored only once.
  • A local index of your memories — message details such as sender, subject, and date; text recognized in your images; scene labels; and your saved or favorited items — is kept in a private on-device database (SQLite, via the open-source GRDB library). This database never connects to a network.
  • Your Google access tokens are stored in the iPhone's Keychain, the system's secure credential store. They are used only to talk to Google and are never written anywhere else.
  • App settings and small preferences — such as which account you connected, your favorites, and a Wi-Fi-only download preference — are stored in the app's standard local settings (UserDefaults). These are not shared with any other app and are not transmitted off the device.
  • Thumbnails are kept in the system cache so the app loads quickly.

We have no access to any of this. It is on your phone.

Photos access

Yesterglow does not read your photo library. The only photo permission it ever asks for is add-only access, and only when you choose to save a Yesterglow share card to your Photos. We use this purely to write the image you asked to save. We never browse, read, or import from your photo library.

Certain device APIs we declare to Apple

Apple requires apps to declare the reasons they use a few common system features, even when no data leaves the device. For full transparency, Yesterglow uses:

  • File timestamps — to read the size and metadata of files in the app's own storage.
  • Disk space — to check that there is enough free space before saving downloaded files.
  • App settings (UserDefaults) — to store the app's own preferences.

None of these involve collecting data about you or sending anything off your device. This matches the app's privacy manifest and our App Store "Data Not Collected" declaration.

Purchases

Yesterglow offers a free tier and optional upgrades:

  • Yesterglow+ (Monthly) — $4.99 per month, with a one-month free trial.
  • Yesterglow+ (Annual) — $39.99 per year, with a one-month free trial.
  • Yesterglow Forever (Lifetime) — $99.99, a one-time purchase, Family Sharing eligible.

All purchases, subscriptions, free trials, renewals, restores, and refunds are handled by Apple through the App Store. Apple processes payment and manages your subscription; Apple's terms and Apple's privacy practices apply to that transaction. Yesterglow does not receive or store your payment information, and there is no Yesterglow account tied to your purchase. Your subscription status is confirmed on your device through Apple's in-app purchase system.

You can manage or cancel a subscription anytime in your iPhone's Settings → your name → Subscriptions, or from within Yesterglow.

How to revoke Yesterglow's access to your Google account

You are always in control of the access you granted. To revoke it:

  1. Disconnect your account inside Yesterglow (in the app's settings), and/or
  2. Go to Google's Account permissions page, find Yesterglow, and choose Remove access.

Revoking access stops Yesterglow from fetching any further mail. Anything already downloaded remains on your device until you delete it or delete the app.

Deleting your data

Because all of your Yesterglow data lives on your device, deleting the app deletes the data. Removing Yesterglow from your iPhone removes its private database, its stored attachments, its cached thumbnails, and its stored Google tokens. There is nothing on a Yesterglow server to delete, because there is no Yesterglow server.

If you only want to clear what is in the app while keeping it installed, you can disconnect your account and remove items from within the app.

Children's privacy

Yesterglow is not directed to children under 13 (or the equivalent minimum age in your country). The app has no accounts and collects no information about anyone, so it does not knowingly gather data from children. The app is rated and intended for a general adult audience managing their own email. If you believe a child has used the app, simply delete it to remove all on-device data.

Security

Connections to Google and Apple use standard encryption (HTTPS/TLS). Your Google access tokens are protected in the iPhone Keychain. Your downloaded files and index live in the app's protected, sandboxed storage on your device. Because we never receive your data, there is no Yesterglow database that could be breached.

Google API Services — Limited Use

Yesterglow's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Specifically: data obtained through the gmail.readonly scope is used solely to provide and improve the on-device features described above, is processed only on your device, is never transferred to others except as necessary to provide those features on your own device, is never used for advertising, and is never read by humans except where required for security or to comply with applicable law.

Changes to this policy

If we change this policy, we will post the updated version at https://www.yesterglow.app/privacy with a new effective date, and — for any change that meaningfully affects how the app handles your information — we will note it in the app or its App Store release notes. Continuing to use Yesterglow after an update means you accept the revised policy.

Contact

Questions about this policy or your privacy? Email us at support@yesterglow.app.