Effective date: September 13, 2026
Beijing Shadow Stitch Technology Co., Ltd. (“we,” “us,” or “our”) respects your privacy. This Privacy Policy explains how we collect, use, store, share, and protect personal information when you use the Coutto Sew mobile app (the “Service”).
Please read this policy carefully before using the Service. By accessing or continuing to use the Service, you acknowledge this Privacy Policy.
1. Scope
This policy applies to the Coutto Sew mobile app and related features, including pattern projection, cutting, stitching, printing, management, and storage. If the Service provides a separate privacy notice, that notice applies where it conflicts with this policy.
2. Information We Collect
We collect information that is reasonably necessary to provide and improve the Service.
2.1 Information you provide
- Contact information: email address, name, and message content when you contact us
- Account and profile information: when you sign in or register, we may receive your phone number (only if you sign in with a phone number, which is currently available on Android), third-party account identifiers (WeChat or Sign in with Apple), and profile details you provide, such as your display name and avatar; an invite code (optional) is used to claim storage bonuses. On iOS, you can sign in with Apple and, in China, with WeChat.
- User content: pattern files, images, and project records you import, create, or manage (primarily processed and stored on your device)
2.2 Information collected automatically
To keep the Service running reliably and improve your experience, we may collect:
| Type | Examples | Purpose |
|---|---|---|
| Device information | device model, OS version, language, display settings, Android ID (Android_ID), OAID, IMEI, MEID, IMSI, GUID, device serial number, MAC address, SIM serial number (ICCID) | device identification, cloud-backup ownership, service security and quality, analytics and anti-fraud |
| Installed app list | installed application information (including whether WeChat or Douyin is installed) or running process information | determine whether WeChat sign-in or Douyin links can be used; analytics and security |
| App information | app version, install source, and feature usage | product improvement |
| Log data | error logs and performance metrics (where applicable) | stability and security |
| Network information | IP address (may be truncated or generalized), network type | security and analytics |
The information we collect differs on Android and iOS. See Sections 2.2.1 and 2.2.2.
In addition, even if you do not sign in, the Service automatically creates an anonymous (guest) account on first launch for features such as the cloud pattern library, cloud backup, credits, and subscriptions (see Section 4). A guest account contains no email address, phone number, or name; it is identified only by a random identifier generated on our servers and does not directly identify you. You can upgrade it to a full account at any time with WeChat or Sign in with Apple, and you can delete it at any time (see Section 8.2).
2.2.1 Android device identifiers, MAC address, and installed app list
To identify the device, prevent abuse and fraud, protect account and cloud-backup integrity, and maintain service quality, the Android app may collect device identifiers including IMEI, device serial number, OAID, MEID, Android ID (Android_ID), IMSI, GUID, MAC address, and SIM serial number. It may also obtain installed application information (the installed app list) or running process information.
- Purpose: identify this device for cloud-backup ownership; detect whether WeChat or Douyin is installed so sign-in or content links can work; analytics, crash reporting, and basic anti-fraud; service security and quality.
- Method: the app and our analytics and sign-in partners collect this information on the device (see Section 4.1).
- Scope: Android only; used only for the purposes in this section and Sections 3 and 4; not for advertising to you and not sold to unrelated parties. The iOS app does not collect these Android identifiers, MAC addresses, or installed-app lists.
Android ID (Android_ID) is read by the app to identify which device a cloud backup belongs to. MAC address, some other identifiers, and the installed app list are collected by our analytics and WeChat sign-in partners (see Section 4.1).
2.2.2 Information collected on iOS
The iOS app does not collect the Android identifiers, MAC addresses, or installed-app lists described in Section 2.2.1. When you use the iOS app, we may collect the information below to provide the Service, keep it secure, and improve it. This information may be linked to your account or device. We do not use it to track you across other companies’ apps, and we do not use it to show you third-party ads.
| Type | Collected | Purpose | Details |
|---|---|---|---|
| Email Address | Yes | Providing the Service | If you sign in with Apple and choose to share your email; if you enter an email to claim a beta membership; if you email us |
| Name | Yes | Providing the Service | The display name and bio on your profile (visible only to you, editable only by you); the name you choose to share when you sign in with Apple |
| Phone Number | No | — | The iOS app does not offer phone-number sign-in, and we do not collect your phone number |
| User Content | Yes | Providing the Service | Pattern and embroidery files, tags, and folders you import or create; if you enable cloud backup, this content is stored on our servers |
| Photos or Videos | Yes | Providing the Service | Profile photos you upload; images captured when you scan a pattern or calibrate projection, which are processed mainly on your device |
| User ID | Yes | Providing the Service | Identifiers used for sign-in, subscriptions, credits, and cloud backup, including the anonymous (guest) account identifier created automatically on first launch, and the account identifier Apple provides when you sign in with Apple |
| Device ID | Yes | Providing the Service, analytics | Used to distinguish devices, understand usage, and help prevent abuse. We do not obtain advertising identifiers for tracking, and we do not use device identifiers to deliver ads |
| Purchase History | Yes | Providing the Service | Your App Store subscription and credit purchases and related entitlements. We do not collect your card number or payment password |
| Product Interaction (Usage Data) | Yes | Analytics | How long you use the app and which screens and features you use, so we can understand product performance and improve the Service |
| Crash Data, Performance Data | Yes | Providing the Service, improving quality | Diagnostic information when the app fails or runs poorly, used to fix problems and improve stability |
| Advertising Data | No | — | We do not use your information for advertising or to track you across apps |
Sign in with Apple: when you choose this option, we receive an account identifier from Apple and any name and email you choose to share, so we can create or sign you into your account. Sign-in credentials are used only to complete sign-in and are not kept long-term on your device. To disconnect Apple from your account if you delete it, we store on our servers the authorization needed for that step, and only for that purpose; it is revoked and deleted when the account is deleted.
2.3 Permissions
To enable certain features, the app may request permissions such as:
- Photos / files: import, export, or save pattern and project files
- Camera: capture or scan pattern-related content
- Network: updates, sync, or loading required resources
You can revoke permissions in device settings. Some features may not work without the relevant permission.
3. How We Use Information
We may use information to:
- Provide, maintain, and improve Coutto Sew and related services
- Respond to inquiries, feedback, and support requests
- Protect the security and integrity of the Service
- Perform aggregated or anonymized analytics to improve user experience
- Comply with applicable laws and regulatory requirements
4. How We Share Information
We do not sell your personal information. We may share information when:
- You give consent
- Required by law or valid legal process
- Service providers help us operate the Service, subject to confidentiality obligations (what they collect is listed in Section 4.1):
- RevenueCat: processes subscription and credit purchase status, entitlements, and anonymous user identifiers for in-app purchases and entitlement delivery
- Alibaba Cloud: provides server hosting for accounts, the cloud pattern library, and cloud backup (stored in the People’s Republic of China)
- WeChat Open Platform: provides WeChat sign-in (only when you choose WeChat sign-in)
- Umeng+: analytics and stability monitoring (see Section 4.1)
- Apple App Store / Google Play: process in-app payments; we do not collect your payment card information
- Business transfers occur (merger, acquisition, or reorganization), with continued protection under this policy
Some providers, such as RevenueCat, may process the information described above outside your country or region. We will take necessary measures (such as notice, consent, and contractual safeguards) to protect your personal information in accordance with applicable law.
4.1 Third-party services we use
We use the following third-party services for sign-in, analytics, and stability. Please also read each provider’s privacy policy.
| Service | Provider | Purpose | Personal information collected | How it is collected | Privacy policy |
|---|---|---|---|---|---|
| Umeng+ analytics and performance monitoring | Umeng Tongxin (Beijing) Technology Co., Ltd. | understand how the product is used, diagnose problems, and help prevent abuse | iOS: device model and OS version, device identifiers, network information, IP address, feature usage, crash and performance information (not IMEI, MAC address, or installed-app information). Android: IMEI, MEID, Android ID (Android_ID), OAID, MAC address, IMSI, GUID, ICCID, device serial number, network information, IP address, installed app list | Collected while you use the Service | Umeng privacy policy |
| WeChat Open Platform | Tencent | WeChat sign-in; on Android, to confirm whether WeChat is installed | iOS: account identifiers needed to complete WeChat sign-in, network status. Android: device identifiers (such as Android ID (Android_ID) and OAID), installed app list (whether WeChat is installed), network status | Collected when you choose WeChat sign-in | WeChat Open SDK personal information rules |
| RevenueCat | RevenueCat, Inc. | subscriptions, credit purchases, entitlement checks | anonymous user identifiers, purchase and subscription status | Collected when you use paid features | RevenueCat Privacy Policy |
5. Storage and Retention
- User content is primarily stored on your device unless you enable cloud sync or backup features
- We retain information only as long as necessary for the purposes described in this policy
- Information is generally stored in the People’s Republic of China. Cross-border transfers, if any, will follow applicable legal requirements
6. Security
We use reasonable technical and organizational measures to protect your information, such as access controls and encryption where appropriate. No method of transmission or storage is completely secure.
7. Your Rights
Depending on applicable law, you may have the right to:
- Access and obtain a copy of your personal information
- Correct or update inaccurate information
- Delete information where legally permitted
- Withdraw consent (without affecting prior processing based on consent)
- Close your account (delete your account in the app; see Section 8)
- Request an explanation of our processing practices
Except for closing your account (which is handled in the app; see Section 8), you can contact us at admin@shadowstitch.cn to exercise these rights. We will respond within a reasonable period after verifying your identity.
8. Account Deletion
You can delete your account in the app. Deletion is permanent and cannot be undone.
8.1 Delete your account
- Entry: In the app, go to Settings → Account → “Delete Account”.
- What happens: Your account, profile, credits, invite records, and cloud pattern backup will be permanently deleted. Purchased credits and subscription benefits will be void and non-refundable. Your on-device pattern library is kept by default.
- Optional: You can also select “Also delete on-device pattern files” to remove local pattern files from your device.
- Confirmation: The app will ask you to confirm (a “Final Confirmation” step). Once confirmed, deletion is executed immediately and cannot be undone.
- Apple Sign-In users: If you signed in with Sign in with Apple, we will simultaneously revoke your authorization with Apple and delete the related sign-in data.
8.2 Delete guest data
If you use the app without signing in (guest mode), you can delete your guest data via Settings → Account → “Delete Guest Data”. This immediately and permanently deletes the anonymous account and its cloud data, with no retention period. Your on-device pattern library is kept by default; select “also delete on-device pattern files” during the deletion flow to remove local files as well.
9. Children’s Privacy
The Service is intended primarily for adults. If you are under 18, please use the Service with guardian guidance. We do not knowingly collect unnecessary personal information from children.
10. Changes to This Policy
We may update this Privacy Policy from time to time. Material changes will be communicated through the app, website, or other reasonable means. Continued use after updates constitutes acceptance of the revised policy.
11. Contact Us
Beijing Shadow Stitch Technology Co., Ltd.
- Email: admin@shadowstitch.cn
- Website: https://shadowstitch.cn
If you have questions, comments, or complaints about this Privacy Policy, please contact us at the email above.
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