Frequently Asked Questions

Yes. The Free plan lets you send up to 3 memos a day, free forever. No credit card registration is required — you can start using it as-is from day one. If you want to send more, the Premium plan (monthly or annual) gives you unlimited sends.

We offer a monthly plan and an annual plan: $2.99/month or $29.99/year (¥500/month or ¥5,000/year in Japan). Please check the App Store in-app purchase screen for pricing in your region. The annual plan works out cheaper than paying monthly.

Tap "View Plans & Subscribe" in the "Premium" section of the Settings screen to open the plan details screen (Paywall). On the Paywall you can review:

• The name, duration, and regional price of the monthly and annual plans
• An explanation of auto-renewal and how to cancel
• Links to the Terms of Use and Privacy Policy
• A "Restore Purchases" button

You will also be offered an upgrade to Premium when you reach the daily send limit on the Free plan.

Yes. The Free plan requires no registration and never expires — you can send up to 3 memos a day for free from day one. No credit card is needed.

Purchasing is entirely optional. If you ever want to send more, upgrade to the Premium plan (monthly or annual) whenever you need it for unlimited sends.

You can cancel from your Apple ID's subscription management screen:

1. Open the "Settings" app on your iPhone
2. Tap your name at the top of the screen
3. Tap "Subscriptions"
4. Select "Simple Memo Premium"
5. Tap "Cancel Subscription"

After canceling, you can keep using Premium features until the end of the current billing period. After that, you can continue on the Free plan (up to 3 memos a day) for free.

Yes. In the Premium section of the Settings screen, tap "View Plans & Subscribe", then tap "Restore Purchases" at the bottom of the Paywall screen that opens. As long as you are signed in with the same Apple ID, your subscription will be restored.

This means product information could not be fetched from the App Store. Please try the following:

1. Check your network connection (Wi-Fi / cellular)
2. Tap the button labeled "Tap to load" to re-fetch the product information
3. Once the re-fetch succeeds, you can proceed straight to the purchase flow
4. If it keeps failing, check your sign-in under iOS "Settings > Apple ID > Media & Purchases"

They are sent as emails to the destination email address you verified in the Settings screen. The sender is Simple Memo <[email protected]>.

The subject is generated automatically using these rules:

• If a subject template is set: template + first line of the memo (e.g., "Simple Memo Today's shopping list")
• If the subject template is empty: the first line of the memo becomes the subject
• If the memo starts with blank lines: the first line containing text becomes the subject
• The subject is truncated at 60 characters

Yes. Enter text in the "Signature" field of the Settings screen, and it will be appended to the end of every email you send, after a -- separator line.

Yes, it was sent. Simple Memo is designed to clear the UI the instant you tap the send button (Send-to-Reset target: 150 milliseconds or less). The memo is sent in the background, and even if sending should fail, it is stored encrypted in the Outbox (unsent queue), so your memo is never lost.

Yes. However, a 1.5-second cooldown is in place to prevent accidental sends. Consecutive taps within 1.5 seconds are ignored, and a "Please wait a moment" toast is shown.

Yes. When you send a memo offline, the message is stored in the on-device Outbox (unsent queue), encrypted with AES-GCM. Once your network connection is restored, sending resumes automatically.

An orange banner appears at the top of the screen reading "Offline — will send when connected". When the network recovers, the banner disappears automatically.

Yes. Outbox messages are stored encrypted in the device's storage, so they are not lost when you close the app or even restart your iPhone. Resending is attempted automatically the next time the app launches, or as a background task.

Yes. Tap the history button (clock icon) at the top left of the main screen to see a list of sent, unsent, and failed memos.

The following is displayed for each memo:

• A preview of the memo body (up to 10 lines)
• Date and time sent
• Status (Sent / Unsent / Failed)

Yes. Tap a memo in the history screen and choose "Resend" to send the same memo again. Because the same message ID is used, duplicate sends are prevented on the server side (idempotency guarantee).

Yes. Tap a memo in the history screen and choose "Share" to bring up the standard iOS share sheet. You can copy it to other apps, share via AirDrop or Messages, and more.

No. Your memo content is never stored on Simple Memo's servers. Memos are sent as email via the Relay API, but no data remains on the server after sending completes. The on-device Outbox and history data are stored only on your device, encrypted with AES-GCM.

Simple Memo encrypts all memo data stored on the device (Outbox and history) with AES-GCM (256-bit).

• The encryption key is stored in the Keychain and protected by the device's Secure Enclave
• Files are covered by Apple's standard Data Protection (completeUntilFirstUserAuthentication)
• The encryption key is never sent off the device

Yes. All communication between the app and the Relay API (Cloudflare Workers) is encrypted with HTTPS (TLS). In addition:

• HMAC signatures: every request is signed with HMAC-SHA256 for tamper detection
• Static API key authentication: a dedicated API key is required to access the server
• Ephemeral URLSession: URLSession uses an ephemeral configuration, so no communication cache, cookies, or URL cache are ever stored
• Idempotency-Key: each send carries a unique message ID so the server can prevent duplicate sends

No. The Relay API only relays the body to Resend for email delivery, and no message body is retained on the server after sending completes. The following data, stored temporarily in Key-Value storage (Cloudflare KV), is also fully hashed and anonymized:

• Email addresses are stored as 128-bit hashes (for rate limiting)
• Verification codes are checked with constant-time comparison and deleted automatically when they expire after 10 minutes
• Device tokens are also hashed and used only for rate-limit accounting

On the device, Outbox and history data are AES-GCM encrypted, with the encryption key stored in the Keychain.

No. When the app moves to the background, a privacy overlay (a cover screen showing only the app icon and title) is automatically placed over the entire screen. No one can see your memo content in the multitasking view.

No. Sensitive information such as email addresses, memo bodies, verification codes, tokens, and URLs is never written to logs in any build, including DEBUG builds. Even error logs record only the kind of error (its type name), not detailed messages.

Yes. Like the Outbox, history data is stored on the device encrypted with AES-GCM. The encryption key is kept in the Keychain and protected at Apple's standard Data Protection level (completeUntilFirstUserAuthentication).

Uninstalling the app deletes all data on the device (Outbox, history, settings, and encryption keys). Keychain data is also deleted on uninstall.

To prevent unauthorized sending to someone else's email address. Verification confirms that you are the owner of that email address. This is an important mechanism for keeping the app safe.

Simple Memo is a memo app dedicated to just three steps: launch → write → send. The memo you type is sent with one tap to the email address you set in advance. There are no complex features such as folder management, tagging, or sync settings. "Jot down what's on your mind right now and send it to your own email" — that is the one thing this app does, as fast and reliably as possible.

• Emailing a shopping list to yourself
• Jotting down an idea that strikes you on the go
• Instantly recording something important you heard in a meeting
• Sending yourself work task reminders
• Noting things to do after you get home, while walking
• Temporarily capturing URLs, phone numbers, addresses, and other info you'll need later

The first time you launch the app, a dialog prompts you to set a destination email address. Set it up as follows:

1. Tap "Go to Settings" in the dialog (or open the Settings screen manually)
2. Enter the email address where you want to receive memos in the "To" field
3. Tap "Verify"
4. Enter the 6-digit verification code sent to that address
5. Verification complete

Yes. Tap "To" in the Settings screen, enter the new email address, and complete verification again. Once the new address is verified, all subsequent memos are sent to the new address.

Tap "Clear Recipient" (shown in red) at the very bottom of the "Email Settings" section of the Settings screen. When you tap "Clear" in the confirmation dialog, all of the following is deleted:

• The configured destination email address
• The verified status (the verified address stored in the Keychain)
• Past verification state (including legacy data)

After clearing, the To field is empty and the verification checkmark disappears. You cannot send memos until you set up and verify an address again. Use this when you want to start over with a different account or redo verification.

Yes. From the "How It Works" section of the Settings screen you can open an illustrated three-step guide:

1. Email setup: register and verify your destination email address
2. Write a memo: the keyboard appears right at launch, ready for immediate input
3. Send: one tap sends it to your destination email

It is translated into each of the 10 supported languages, including English and Japanese.

Any address that can receive email works — all email services are supported. Gmail, Outlook, Yahoo Mail, iCloud Mail, company email, custom-domain email, and more, with no restrictions.

Text that is prepended to the subject of each email you send. For example, if you set "Simple Memo" and the first line of your memo is "Today's shopping", the subject becomes "Simple Memo Today's shopping". Leave it empty and the first line of the memo becomes the subject as-is.

Yes. In the "Sound & Haptics" section of the Settings screen you can toggle the send sound on or off. Even with the sound off, haptic feedback continues to work. Note that in silent mode the sound is muted automatically regardless of the setting.

Yes. The app follows your iOS system setting and switches between light and dark mode automatically. There is no app-specific theme switcher; it always follows the system setting.

No. Simple Memo is an independent app inspired by the original Captio and has no relationship with Captio's developer. It aims to recreate and build on the experience Captio offered: launch → type immediately → one-tap send → instant clear.

No. Simple Memo - for Obsidian is an independent app developed by YURIKA, K.K. and is not an official Obsidian app or plugin. The Obsidian integration automatically appends your sent memos to a note in your own Obsidian vault and requires no Obsidian account or plugin. Obsidian is a trademark of Dynalist Inc.

Yes. Basic Apple Watch support (quick capture) has been available since v3.4. You can send a memo to your own email in as few as 2 taps from Apple Watch, with voice dictation and Smart Stack support (advanced Watch automation is not supported). Due to watchOS platform rules, dictation cannot auto-start on launch (you tap the mic first). See the Apple Watch page for details.

Simple Memo recreates the core experience of the original Captio while improving and extending it in the following ways:

• Outbox (unsent queue): automatic resending so memos are never lost, even offline
• AES-GCM encryption: all on-device data is encrypted
• Privacy overlay: hides memo content in the app switcher
• 10 languages: including Japanese and English (RTL supported)
• Email address verification: 6-digit code verification to prevent abuse
• Send animation: page-turn style 3D animation + haptics

No. There is no feature for importing data from the original Captio. Simple Memo is an app independent of Captio, so the data is not compatible.

No. Simple Memo specializes in sending text memos fast and does not support image attachments. To save photos, please use Apple's built-in Photos or Notes apps. Simple Memo is a dedicated tool for "capturing a thought as text, right away."

• iPhone (iOS 16.0 or later)
• iPad (iPadOS 16.0 or later)

The target for Time-to-Text — from launching the app to being able to type — is 500 milliseconds or less. In real-world measurements, most devices record around 200–300 milliseconds. The app skips Storyboards and initializes UIKit directly to achieve the fastest possible launch.

No external SDKs are used anywhere in the "primary data path" — memo encryption (CryptoKit), key storage (Keychain Services), and networking (URLSession / Network.framework) are built entirely on Apple's first-party frameworks.

Since v2.4, the app additionally uses the GoogleSignIn-iOS SDK and Firebase Authentication SDK for an optional onboarding shortcut (importing your email from a Google account), plus the Firebase App Check SDK to protect the backend API against unauthorized access. Usage analytics are sent to our own /v1/analytics/event endpoint; no third-party analytics SDKs are used.

The following 10 languages are supported: Japanese, English, Spanish, French, German, Portuguese, Russian, Chinese (Simplified), Chinese (Traditional), and Arabic.

From the "Language" section of the Settings screen. Changes take effect across the entire app immediately (the screen reloads automatically).

Yes. When you select Arabic, the text direction, UI layout, and navigation bar button placement all switch automatically to RTL (right-to-left).

Simple Memo is designed to keep background network activity to a minimum. Outbox resending uses iOS's BGTaskScheduler, which lets the system pick an appropriate moment (while charging, on Wi-Fi, etc.) to run it. The app never runs continuously in the background.

Please check the following:

• There are no typos in the email address
• It has not been filtered into your spam/junk folder
• The sender is Simple Memo <[email protected]>
• Verification codes expire after 10 minutes. If expired, request a new code
• You can enter the code up to 5 times. After 5 failed attempts, request a new code

Enter and verify a destination email address from the Settings screen. You cannot send memos until verification is complete.

Verification of the destination email address has not been completed. Tap the "Verify" button next to the email address in the Settings screen and complete the verification flow. If you changed the email address, the new address also needs to be verified.

This appears when many memos are sent in a short time. The following limits apply:

If you reach a limit, wait a while and try again. Messages saved in the Outbox are resent automatically once the limit lifts. With normal use (a few to around 10 memos a day) you will never hit these limits.

The Relay API server is experiencing a temporary problem. It usually recovers within a few minutes. Your memo is safely stored in the Outbox and will be resent automatically after recovery. If the problem persists for a long time, please contact support.

Please check the following:

1. The destination email address is correctly verified
2. Your network connection is stable
3. Check your spam/junk folder
4. Make sure your email service's filtering settings are not blocking mail from simplememofast.com

Please check the following:

• Your network connection is stable
• The destination email address is verified
• Each message is retried up to 5 times. A message that fails 5 times stops as "max retries exceeded"
• Try resending manually from the history screen

Memos saved in the Outbox are not lost. A memo is encrypted and saved to the Outbox the moment you tap the send button, so after a crash, simply relaunch the app and resending is attempted automatically.

This happens when the server's response never reaches the device — due to a network timeout, backgrounding, or similar — so the app judges the send as "failed" even though it actually succeeded. v1.5 improves this as follows:

• Immediate retry after 5 seconds: even when treated as a timeout, one automatic background resend is attempted right away
• Instant retry on app return: the moment you come back to the app from the home screen, any unsent messages are resent immediately
• Duplicate-send prevention: every send path uses the same Idempotency-Key, so even if the message had actually reached the server, the email is never sent twice
• Automatic history repair: when a resend succeeds, the corresponding history entry is automatically updated to "Sent"

So even if "Unsent" is shown briefly, exactly one email is delivered correctly.

Yes. Since v1.5, each send is tracked individually by its history entry ID, not by its body text. Even if you send the same short message like "OK" three times in a row, each of the three history entries is correctly marked "Sent" (earlier versions could misjudge based on matching body text).

Please contact us via:

• Email: support@simplememofast.com
• App Store review: via the in-app rating dialog or the review section on the App Store

• Terms of Service: https://simplememofast.com/en/terms
• Privacy Policy: https://simplememofast.com/en/privacy

No. There is no feature for importing data from the original Captio. Simple Memo is an app independent of Captio, so the data is not compatible.