Ground We Share ("GWS", "the app"), provided by Ziqian Liu, helps two people find shared interests through local computation and manually exchanged messages. This policy covers the app, this website, and support communications.
GWS has no user accounts or login. The developer does not operate a server to receive selections, compute matches, or relay invitation and reply messages. Matching is computed on your device. Website hosting and support communications are described below.
The app does not send your selections, matching results, or cryptographic keys to us. It contains no analytics SDK, crash-reporting SDK, or advertising SDK, and requires no account. Website visits, voluntary support emails, and Apple's testing services are described below.
Clipboard. GWS reads clipboard text only after you explicitly tap an import or clipboard-reading action, then checks and imports the invitation or reply. It does not monitor the clipboard in the background or keep a separate clipboard history. If reading or recognition fails, you can paste and edit the message manually before confirming the import.
GWS supports movies, music artists, countries, and relationship boundaries. It uses private set intersection (PSI) to find an overlap without exchanging the full lists in readable form. In the current one-to-one workflow, the invitation sender computes the result locally after receiving a reply. The responder does not receive the result in the app.
You exchange invitation and reply text through a messaging service of your choice. These messages contain cryptographic data and may also reveal the topic, prompt, and list sizes; not every part of a message is encrypted. Your messaging provider and recipients handle the text you send. GWS does not relay it through a developer-operated server.
Data flow. Your phone creates an invitation → you send it through your chosen messaging app → the other phone computes a reply → you exchange that reply through your chosen channel → the invitation sender's phone computes the result. The external messaging channel handles the messages; this is not a direct phone-to-phone connection managed by GWS.
Sharing results. You can preview locally generated PNG images and choose to share them through the system share sheet. These are readable results, not encrypted replies. Images contain the question and shared choices, including any relationship-boundary results, but exclude round notes, full selection lists, keys, and passphrases. You choose the destination app and recipient. Recipients may save or forward images; GWS cannot recall them. Opening a share sheet does not confirm delivery.
Your selections and the cryptographic keys used to compute the match are stored locally on your device using Capacitor Preferences (UserDefaults on iOS and SharedPreferences on Android). This is app-private storage, not an encrypted vault.
In-progress rounds. For an invitation sender, the app retains the selected items and cryptographic material needed to process a reply. A responder's session retains protocol messages needed for the return step. Pending sessions do not automatically expire. Starting a replacement round may overwrite the current session after confirmation.
Results, reply summaries, and notes. After the sender computes a result, the app removes that round's private key and full selected list from the active session record. Local result history contains the topic, question, shared items, the sender's selection count and time where available, and an optional round note. A responder keeps a separate local summary marked as replied, with no result or full selection list. Records are kept until you delete them; there is no automatic ten-record limit. Round notes stay local and are excluded from invitation/reply messages and exported result images.
Interface preferences. Your language preference is stored locally in app or browser storage. Changing the interface language does not translate your custom questions or stored record text.
Abandoning an invitation. You can abandon a pending invitation. This removes the current session and the cryptographic material needed to process its reply, so a later reply can no longer be used to calculate that comparison result. This action does not recall messages you have sent or remove earlier backups. Deleting history is a separate action and preserves pending sessions.
Temporary images. Sharing a PNG creates files in the app's cache, without automatically saving them to your photo library. Files may remain after the share sheet closes so the receiving app can read them. On a later launch, GWS attempts to remove its exports older than 24 hours; the operating system may reclaim cached files earlier. Files you save or share outside GWS are not removed by this cleanup.
Your controls. You can edit notes and delete individual records or all history in the app. Deleting history preserves pending invitation/reply sessions; deleting a completed record also removes its saved last-result display when applicable. The result screen's "Start over" action clears the current session when applicable. Local data, including pending-round keys, results, reply summaries, and notes, may be included in device backups, including iCloud backups, according to your operating system and settings. Android backup is enabled, but cloud backup and device-to-device transfer are not guaranteed. Deleting records does not erase earlier backups or shared messages/images. We cannot retrieve or remotely delete your local data.
Searching the bundled lists, selecting items, generating an invite, and computing a result run locally and do not require an internet connection or a developer-operated service. GWS does not send your selections, matching results, or cryptographic keys to us. The movie, music, and other lookup lists are bundled inside the app itself.
Opening external links, including "↗" links to Wikidata, or visiting this website requires network access. The destination service may receive information such as your IP address and browser details. Exchanging text through a messaging service also uses that service's infrastructure.
We do not sell app data or use it for advertising. Messaging services, backup services, and external websites operate under their own policies. Wikidata is covered by the Wikimedia Privacy Policy.
The public policy website is hosted on GitHub Pages; this bundled copy can be read offline. We add no analytics scripts, advertising, or tracking cookies. GitHub may process technical request information, including IP addresses, to provide and secure hosting; see the GitHub Privacy Statement.
If you use a TestFlight beta, Apple collects testing information and may share crash reports, usage information, and feedback with the developer under TestFlight & Privacy. This is separate from the app's own local processing.
If you email us, we receive your email address and whatever you include. We use this information to respond and resolve your request, and retain it only as needed for support or legal obligations. Email providers process delivery and storage. Please avoid sending private selections, invitation text, or reply text. You can contact us to request access, correction, or deletion of support correspondence. Depending on your location, you may have additional privacy rights, including the right to complain to your local data protection authority.
The app is not directed at children and contains no advertising or in-app purchases. We do not knowingly request personal information from children. If a child has sent personal information to support, please contact us so we can address it.
If this policy changes, we will update the policy date above and explain material changes. We will provide additional notice or obtain consent where required.
Developer: Ziqian Liu. Questions about privacy or support: admin@sceneswemet.com. For support, use the same email address.
半分知己（Ground We Share，以下简称“本应用”）由 Ziqian Liu 提供，通过本地计算与手动交换消息，帮助两个人发现共同点。本政策涵盖本应用、本网站和支持通信。
本应用没有用户账号或登录。开发者不运营接收选择、计算匹配或中转邀请与回传消息的服务器；匹配在你的设备上计算。网站托管和支持通信另见下文。
应用不会向我们发送你的选择、匹配结果或密码学密钥，没有集成分析 SDK、崩溃上报 SDK 或广告 SDK，也不需要账号。网站访问、主动发送的支持邮件及苹果测试服务的情况见下文。
剪贴板。只有你主动点击导入口令或读取剪贴板的操作时，GWS 才读取剪贴板文字，校验并导入邀请或回传；不会在后台监听，也不保存单独的剪贴板历史。读取或识别失败时，你可以手动粘贴、编辑消息，再确认导入。
应用支持电影、音乐艺人、国家和关系边界，使用隐私集合求交（PSI），无需以可读形式交换完整清单即可计算交集。在当前一对一流程中，邀请发起方收到回传后在本地计算结果；响应方不会在应用中收到结果。
你通过自己选择的聊天服务交换邀请与回传文字。这些消息包含密码学数据，也可能透露场景、提示语和清单条目数量，并非所有内容都经过加密。聊天服务及收件人会处理你发送的文字，GWS 不通过开发者运营的服务器中转消息。
数据流向。你的手机生成邀请 → 你通过选择的聊天应用发送 → 对方手机计算回传 → 你们通过选择的渠道交换回传 → 发起方手机计算结果。外部聊天渠道会处理消息，这不是 GWS 管理的手机直接连接。
分享结果。你可以预览在本机生成的 PNG，再选择通过系统分享面板发送。图片是可读明文结果，不是加密回传；包含问题和共同选择，也可能包含交往边界结果，但不含轮次备注、完整选择清单、密钥或口令。目标应用和收件人由你选择。收件人可以保存或转发，GWS 无法撤回。打开分享面板不代表消息已送达。
你的选择内容与用于计算匹配结果的密钥材料，通过 Capacitor Preferences 保存在你自己的设备上（iOS 使用 UserDefaults，Android 使用 SharedPreferences）。这是应用私有存储，不是加密保险库。
进行中的轮次。发起方设备保存所选条目及处理回传所需的密码学材料；响应方会话保存回传步骤所需的协议消息。待完成会话不会自动过期。开始替代轮次时，可能在确认后覆盖当前会话。
结果、回复摘要和备注。发起方算出结果后，应用会从当前会话记录移除该轮私钥与完整选择清单。本地结果历史包含主题、问题、共同项、可用的发起方选择数量和时间，以及可选的轮次备注。响应方单独保留标为“已回复”的本地摘要，不包含结果或完整选择清单。记录保留到你主动删除，不再自动限制为十条。轮次备注仅保存在本机，不进入邀请、回传或结果图片。
界面偏好。语言偏好保存在本机的应用或浏览器存储中。切换界面语言不会翻译自定义题目或已保存记录的原文。
放弃邀请。你可以放弃等待中的邀请。这会清除当前会话及处理回传所需的密码学材料，之后即使收到回传口令，也无法计算这一轮结果。此操作不会撤回已发送的消息，也不会删除旧备份。删除历史记录是另一项操作，等待中的会话仍会保留。
临时图片。分享 PNG 时会在应用缓存中生成文件，不自动写入相册。分享面板关闭后，文件可能继续保留，供接收应用读取。GWS 在后续启动时尝试清理超过 24 小时的本应用导出；系统可能更早回收缓存。你另行保存或分享出去的文件不会被此清理删除。
你的控制方式。你可以编辑备注、删除单条或全部历史。删除历史会保留待完成的邀请/回复会话；删除已完成记录时，适用的上次结果显示也会一并移除。结果页的「重新开始」在适用时清除当前会话。本地数据，包括待完成密钥、结果、回复摘要和备注，可能依操作系统及设置进入系统备份（包括 iCloud）。Android 备份已启用，但不保证云备份或设备间迁移可用。删除记录不会清除旧备份或已经分享的消息、图片。我们无法取回或远程删除你的本地数据。
搜索内置词表、选择条目、生成邀请和计算结果均在本地进行，不需要联网或开发者运营的服务。GWS 不会向我们发送你的选择、匹配结果或密码学密钥。电影、音乐等词表数据已打包在应用内部。
打开外部链接（包括通往 Wikidata 的「↗」链接）或访问本网站需要联网，目标服务可能收到 IP 地址、浏览器信息等数据。通过聊天服务交换文字也会使用该服务的基础设施。
我们不出售应用数据，也不将其用于广告。聊天、备份和外部网站适用各自的政策。Wikidata 适用 Wikimedia 隐私政策。
公开隐私政策网站由 GitHub Pages 托管。我们没有添加统计脚本、广告或追踪 Cookie。GitHub 可能为提供及保护托管服务处理 IP 地址等技术请求信息，详见 GitHub 隐私声明。本地随应用打包的政策副本可离线阅读。
如果你使用 TestFlight 测试版，苹果会收集测试信息，并可能向开发者提供崩溃报告、使用信息及反馈，详见 TestFlight 与隐私。这与应用自身的本地计算是不同的处理活动。
如果你向我们发邮件，我们会收到你的邮箱地址及你提供的内容，用于回复和处理请求，并仅在支持或法律义务所需期间保留。邮件服务商负责邮件传输及存储。请避免发送私人选择、邀请或回传文字。你可联系我们请求访问、更正或删除支持通信。依据所在地法律，你可能还享有其他隐私权利，包括向当地数据保护机构投诉的权利。
应用不面向儿童设计，不含广告或应用内购买。我们不会主动向儿童索取个人信息。如果儿童已通过支持渠道发送个人信息，请联系我们处理。
本政策变更时，我们会更新政策日期并说明重大变化，依法提供额外通知或取得同意。
开发者：Ziqian Liu。隐私及支持邮箱：admin@sceneswemet.com。支持请求也请发送至该邮箱。