Privacy Policy

Data Storage

All caffeine intake logs and drink entries you create in CaffeineHalf are stored on your device; the caffeine decay curve is not stored but recalculated on your device from those entries each time it is shown. CaffeineHalf does not send your data to any server of ours. Data leaves the device only in these ways: iCloud sync (below), Apple Health if you turn it on (see "Apple Health" below), your paired Apple Watch, exporting a CSV file (Full Access) to a location you choose, and your device's own backups.

• iCloud sync — if you are signed in to iCloud on the device, CaffeineHalf automatically stores your intake entries, saved drinks, deleted-entry markers and main settings (bedtime, half-life, thresholds, daily limit) in your own iCloud key-value storage and syncs them between your devices using the same Apple Account. The app has no separate sync switch; to stop it, turn off iCloud for CaffeineHalf in iOS Settings or sign out of iCloud. This data is held by Apple under your Apple Account, not by us
• Apple Watch — the app sends your intake entries from the last 3 days and the settings needed to draw the caffeine curve (half-life, bedtime, daily limit) to its app on your paired Apple Watch over Apple's Watch Connectivity
• Widgets — the same entries (last 3 days) and settings are shared with the app's own widgets through an App Group on your device
• CSV export (Full Access) writes your entries (date and time, drink name, caffeine amount) to the location you pick in the iOS file picker; once saved there, the file is under that location's control
• No backup to CaffeineHalf servers — we operate no servers
• If you delete the app, your entries and settings are removed from your device (see "Deleting Your Data" below)
• App preferences are stored in UserDefaults on your device (main settings are also synced through iCloud as described above)

Data We Do NOT Collect

We (the developer) do not receive any of the following, and CaffeineHalf's own code does not send it to any server of ours or to advertising services. Your caffeine entries do leave the device in the ways you control that are listed in "Data Storage" above (your own iCloud, Apple Health if you turn it on, your paired Apple Watch, a CSV file you export, and your device's backups). This list does not cover the Google ad SDKs included in the free version, which collect data of their own (see "Analytics and Tracking" and "Advertising" below):

• Personal identifiers (name, email address, phone number) — the app does not ask for them
• Caffeine or health data — not sent to us or to advertising services. Your entries are stored in your own iCloud, written to Apple Health if you turn the integration on and allow writing, and sent to your paired Apple Watch, as described in "Data Storage" and "Apple Health"
• Device identifiers by CaffeineHalf itself — the app's own code does not read the advertising ID. In the free version, the app asks for App Tracking Transparency permission on behalf of Google's ad SDK (see "Advertising" below).
• Location data — the app's own code requests no location permission and reads no location. In the free version, Google's ad SDKs declare that they may collect approximate location
• Usage analytics — the app's own code contains no analytics. In the free version, Google's ad SDK declares that it may collect product interaction data, and the app's privacy manifest declares this data for advertising and analytics purposes
• Crash reports — the app's own code sends none. In the free version, Google's ad SDK declares that it may collect crash data, and the app's privacy manifest declares this for analytics purposes
• Contacts, photos, microphone or camera — the app requests none of these permissions

Apple Health

Apple Health integration is off until you turn it on in the app. When you turn it on, iOS asks for your permission to:

• Write dietary caffeine — while the integration is on, the app asks Apple Health to save each intake entry as a caffeine sample. The sample is saved only if you allowed writing caffeine; the integration can be on even if you did not allow it, and the app does not check whether each save succeeded. When you delete an entry on this device while the integration is on, the app also asks Health to remove its sample; if writing is not allowed or the removal fails, the sample stays in Health while the entry is still deleted in the app. Samples are not removed from Health if you delete entries after turning the integration off, or if the deletion comes from another device through iCloud sync. Check and delete samples in the Health app
• Read sleep analysis and resting heart rate — used only on your device to show correlation insights between your caffeine and sleep/heart rate in the history screen

Health data read by the app is not sent to any server, is not shared with advertising services, and is not stored in iCloud by CaffeineHalf. You can change or revoke these permissions at any time in the Health app or iOS Settings, and turn the integration off in the app.

Analytics and Tracking

CaffeineHalf itself contains no analytics code. The only third-party SDKs are Google Mobile Ads and Google User Messaging Platform (for ad consent), used for advertising in the free version. These SDKs declare in their own privacy manifests that they may collect data such as device identifiers (declared for tracking and analytics purposes), approximate location, crash data, performance data, other diagnostic data and product interaction data, according to your consent choices; see "Advertising" below. Apart from these SDKs, the app communicates only with Apple services: the App Store through StoreKit (loading the Full Access product, purchase, and Restore Purchases) and your iCloud key-value storage for sync (see "Data Storage" above). The optional AI estimate of a custom drink's caffeine runs on the device with Apple Intelligence (on supported devices only), and the drink name is not sent to us.

• No Firebase, no Amplitude, no Mixpanel, no Crashlytics
• No attribution tools, A/B testing or remote configuration services
• Your caffeine entries are never sent to advertising services

Advertising

The free version of CaffeineHalf shows a banner ad served by Google AdMob (Google Mobile Ads SDK). Once the app has confirmed your Full Access purchase with the App Store, no ads are shown and the ad SDK is not started. When the app launches without a confirmed Full Access purchase, it also checks the app's App Store purchase record to recognize buyers of an earlier paid version. If that record cannot be retrieved or verified (for example, the App Store cannot be reached), the app temporarily treats you as having Full Access, does not show ads, and checks again on the next launch. If the record is verified and shows you did not buy an earlier paid version, a Full Access purchase that could not be verified is treated as not purchased, and ads are shown; use "Restore Purchases" to check again.

• Google may collect and use device and ad-related data (such as the device's advertising identifier, IP address, and ad interaction data) to deliver and measure ads, according to your consent choices
• Where required (for example in the EEA and UK), the app asks Google's User Messaging Platform to show a consent form before ads are requested. If the consent status cannot be updated or the form cannot be shown, the app falls back to the consent status Google's SDK has stored from an earlier session and requests ads only if that status allows it. Where consent is required, you can change your choice later with the "Ad Privacy" button, shown above the banner ad and in the Privacy section of the Settings screen (it appears only in the free version and only when the consent rules for your region require it)
• In the free version, after Google's consent message (where one is required), iOS asks whether to allow the app to track you (App Tracking Transparency). The prompt is shown once. If you allow it, Google's SDK may use the device's advertising identifier to personalize and measure ads. If you decline, ads are still shown, the advertising identifier is not shared, and every feature of the app keeps working. You can change your choice at any time in iOS Settings > Privacy & Security > Tracking. The prompt is not shown once Full Access is confirmed
• Ads are requested with a general content rating

Purchases and Payments

CaffeineHalf offers an optional one-time in-app purchase ("Full Access") via the App Store that unlocks unlimited history, CSV export, unlimited saved drinks, multiple what-if comparisons, and removes ads. All payment processing is handled entirely by Apple through StoreKit 2.

• CaffeineHalf never sees, receives, or stores your payment information
• No credit card numbers, Apple ID credentials, or financial data passes through CaffeineHalf
• Purchase status is verified through StoreKit 2's transaction verification, using Apple's App Store; the app also checks the App Store receipt to recognize users who bought an earlier paid version

Deleting Your Data

You can remove intake entries, saved drinks and what-if scenarios one by one inside the app. The what-if list shows scenarios for all dates, and each can be deleted. In the free version the history screen shows only the last 7 days of entries; older entries stay stored and can be deleted together with the "Delete N records older than 7 days" button below the history list (or unlocked with Full Access). Deleting the app removes the entries and settings stored inside the app on your device, but not the copies in your iCloud key-value storage (if you reinstall while signed in to iCloud, your entries, saved drinks and settings come back from iCloud), data already written to Apple Health, CSV files you exported, or the small Keychain marker for an earlier paid version. Entries you delete in the app are also removed from your other devices through iCloud sync. The app keeps only a limited number of deletion records in iCloud (up to 2,000), so after many deletions, a device that has not synced since before those deletions may bring some deleted entries back; if that happens, delete them again. For entries you delete one by one on this device while Apple Health integration is on, the app also asks Apple Health to remove the sample; if writing to Health is not allowed or the removal fails, the sample stays in Health. Entries removed with the "Delete N records older than 7 days" button, entries deleted with the integration off, and entries deleted on another device and synced through iCloud stay in Health until you delete them in the Health app. Copies kept in your iCloud key-value storage are controlled by your Apple Account. Deleting entries and saved drinks in the app while signed in to iCloud removes them from that storage, but the app has no control to remove your synced settings or its deletion records (lists of deleted entry IDs, up to 2,000) from iCloud. Data already written to Apple Health can also be deleted in the Health app. Daily water totals are kept only on this device; you can lower today's total with the minus button on the dashboard, but the app has no control to delete earlier days' water totals other than deleting the app. CSV files you exported are saved elsewhere and are not removed; delete them in the location where you saved them. We hold no copy of your data on any server, so there is nothing for us to delete remotely. For data handled by Google for ads, use Google's own controls.

If iCloud Backup is enabled on your device, your app data may be included in your own iCloud backup under Apple's control.

Children's Privacy

We, the developer, do not receive or knowingly collect personal information from anyone, including children under the age of 13: the app has no account system and does not send your entries to any server of ours. In the free version, however, Google's ad SDKs may collect data such as device identifiers, approximate location, diagnostic data and ad-related data from any user, including children, according to the consent choices, as described in "Analytics and Tracking" and "Advertising" above. Ads in the free version are requested with a general content rating. Buying Full Access stops ads.

Changes to This Policy

If we update this Privacy Policy, the revised version will be posted at this URL with an updated effective date. We will notify users of material changes through an App Store update description.

Continued use of CaffeineHalf after any changes constitutes acceptance of the updated policy.

Informational Tool Disclaimer

CaffeineHalf is an informational tool for tracking caffeine intake and estimating half-life decay. It does not provide medical advice, diagnose conditions, or replace professional guidance. Always consult a healthcare professional for medical concerns.

CaffeineHalfはカフェイン摂取量と半減期を追跡する情報ツールです。医学的助言や診断は行いません。医療に関するご相談は専門家にお問い合わせください。

日本語プライバシーポリシー概要

CaffeineHalfは摂取記録や設定を端末内に保存し、開発者のサーバへの送信は行いません。iCloudにサインインしている場合は、記録・保存した飲み物・設定がご自身のiCloud（キー値ストレージ）にも自動で保存され、同じApple Accountの端末間で同期されます（停止はiOSの設定でiCloudをオフにします）。Apple Health連携をオンにした場合のみ、カフェイン量の書き込みと、睡眠・安静時心拍数の読み取りの許可を求めます。読み取ったデータは端末内での相関表示にのみ使います。アカウント登録は不要です。無料版ではGoogle AdMobによるバナー広告が表示され、Googleが同意設定に応じて端末情報や広告識別子などを取得する場合があります（フルアクセスを購入すると広告は表示されません）。無料版では、Googleの同意メッセージ（必要な地域のみ）のあとに、iOSがトラッキングの許可（App Tracking Transparency）を1回だけ尋ねます。許可するとGoogleのSDKが広告識別子を広告の最適化と効果測定に使う場合があります。許可しなくても広告は表示され、広告識別子は共有されず、アプリの機能はすべて使えます。選択はiOSの「設定 > プライバシーとセキュリティ > トラッキング」でいつでも変更できます。

アプリ内課金の決済はAppleのApp Storeを通じて処理され、CaffeineHalfが決済情報を取得することはありません。データの削除はアプリ内での記録削除（無料版で表示されない7日より古い記録は、履歴画面の一括削除ボタンで削除可能）で行えます。アプリを削除すると端末内のデータは消えますが、iCloudに保存された記録・保存した飲み物・設定（再インストールすると戻ります）、Apple Healthに書き込んだデータ、書き出したCSVファイル、旧有料版の購入を示すKeychainの印は残ります。iCloud上の設定と削除の記録はアプリ内では消せません。Healthのデータはヘルスケアアプリで、CSVは保存先で削除してください。広告の同意設定は、広告の上と設定画面の「広告プライバシー」ボタン（同意が必要な地域の無料版のみ表示）から変更できます。

本アプリに関するお問い合わせは下記の連絡先までお願いいたします。