CaffeineJitter is a clean and privacy-focused offline caffeine tracking tool that helps users monitor real-time caffeine metabolism and evaluate caffeine’s impact on sleep in a fully local environment. Log your daily coffee, tea, and energy drink intake, track real-time residual caffeine levels, view visualized metabolism curves, and calculate safe bedtime countdowns — all without any network connection, account login, or data uploads. Designed for coffee enthusiasts, night-shift workers, and sleep-sensitive users, CaffeineJitter delivers an intuitive, ad-free, and precise caffeine monitoring experience to balance coffee enjoyment and high-quality sleep.

App Features

Real-Time Caffeine Metabolism Calculation & Visual Curve Track your bodily caffeine changes with a professional half-life decay algorithm. The app automatically calculates real-time residual caffeine milligrams after you record each drink intake and generates a smooth 24-hour metabolism curve. Intuitively observe how caffeine gradually fades in your body and grasp the dynamic impact of every cup of coffee or energy drink.
Preset & Custom Drink Library Built-in offline high-precision presets for common drinks including Americano, Latte, Espresso, Red Bull, and regular tea with standard caffeine content and unit pricing. Users can freely customize drink volume, caffeine milligrams, exact drinking time, and personal unit price to fit diverse drinking habits and achieve fully accurate personalized calculation.
Safe Sleep Countdown Calculator Automatically judge sleep impact based on professional caffeine safety thresholds. The app precisely calculates the exact time when residual caffeine drops to a sleep-safe level and displays a real-time safe bedtime countdown. Clearly distinguish sleep risk levels and help users avoid insomnia caused by excessive caffeine intake.
Daily Caffeine Intake Warning Follow the WHO official daily caffeine intake standard (400mg upper limit). Automatically accumulate daily caffeine intake and trigger gentle in-app reminders when exceeding the safe threshold. Effectively help users control daily caffeine intake and avoid physical discomfort caused by overconsumption.
Offline Monthly Consumption Statistics Record all drinking behaviors locally and generate exclusive monthly statistical reports. Track total monthly drink times, total caffeine intake, and monthly coffee consumption costs. Help users intuitively understand their coffee drinking habits and effectively manage daily beverage expenses.
Full Local Data Storage & Privacy Protection All drinking records, calculation data, statistical content, and user settings are permanently stored locally on your iPhone. No network access, no cloud synchronization, no personal data collection and no information leakage. Every piece of your caffeine data is completely private and exclusively controlled by you.
Polished Native UI & System Adaptation Adopt minimalist and advanced iOS native design style with unified rounded corners, delicate animations, and high-level color matching. Support automatic light and dark mode switching, fully adapt to all iPhone screen sizes, and provide smooth, clutter-free and elegant user interaction experience.

Technical Support

Thank you for downloading CaffeineJitter. We are committed to providing users with stable, accurate, private and pure offline caffeine tracking services. If you encounter any technical problems, abnormal display or functional errors during use, please refer to the following guidelines for troubleshooting.

System Requirements

Platform: Optimized for iOS (iPhone only).
Network Environment: 100% full offline support. All core calculation, recording, statistics and query functions can be used normally without an internet connection. No user data will be uploaded, synchronized or shared in any form.
Permissions: No sensitive system permissions required. The app does not access location, camera, microphone, photo library, contacts or other private data.
Performance: For the most accurate calculation and smoothest animation experience, please update your iOS system to the latest official version.
Storage: Please ensure your device has sufficient free storage space to save local drinking records and statistical cache data.

Frequently Asked Questions

The app lags or crashes unexpectedly Close redundant background applications to release device memory and running resources. Check whether the iPhone storage space is sufficient. Restart the app or your device to clear temporary cache. If the problem persists, reinstall the app, and your local data will not be affected under normal circumstances.
Caffeine calculation data is abnormal or inaccurate Confirm that the selected drink type, custom caffeine content and drinking time are filled correctly. The app adopts a standard 5.5-hour caffeine half-life algorithm, and individual physical differences are not included in the universal calculation model. Recreating the drink record can refresh the calculation data.
Safe sleep countdown time displays incorrectly The sleep safety threshold is based on the universal standard of 20mg residual caffeine. Newly added drink records will automatically refresh the countdown data. You can restart the app to synchronize the latest metabolic calculation results if data delay occurs.
Will app updates erase my local records? Official version updates will not clear any user’s local drinking records, caffeine data and statistical data. To avoid accidental data loss in rare cases, it is recommended that you check and back up important data before updating.
Monthly statistical data display is incomplete The statistical page automatically counts data based on the system calendar month. New records will be updated in real time. You can exit and re-enter the statistics page to refresh all data.
Dark mode interface display error Switch the system light/dark mode again or restart the app to fix individual visual glitches. Theme switching only affects UI display and will not change any local data.

Contact Support

If you have functional suggestions, usage questions or technical faults that cannot be solved independently, please contact our support team through the official email:
Support Email: 18389836001@163.com
We will check and reply to your feedback within 24–48 hours to help you solve problems and optimize your using experience.
Thank you for using CaffeineJitter — Track your caffeine metabolism, protect your sleep quality and enjoy coffee wisely! ☕️

评论

发表评论

此博客中的热门博文

ErrorBook Official Technical Support Blog

 ErrorBook is a clean and privacy-focused offline study tool that lets learners organize, review, and archive wrong questions in a fully local environment. Build your personal subject question bank, record study mistakes with text or images, tag subjects freely, and track your review progress — all without any network connection, account login, or data uploads. Designed for students of all stages, ErrorBook delivers a pure, distraction-free learning experience focused entirely on knowledge consolidation. App Features Dual Wrong Question Recording : Record your study errors with two flexible offline methods. Type detailed question content manually or upload screenshots and photos from your device gallery. All content is saved locally instantly, helping you quickly capture every knowledge gap during daily learning and exam preparation. Custom Subject Tag Management : Organize your question bank with fully customizable subject tags. Create, edit, rename, sort, and delete tags to match...
阅读全文
 Random:Draw is a clean and privacy-focused offline random selection tool that helps users conduct fair random draws, name picking, and team grouping in a fully local environment. Create custom participant lists, perform unbiased random selections, generate balanced random groups, and save your commonly used templates and draw history — all without any network connection, account login, or data uploads. Designed for classroom activities, campus clubs, team building, party games, and daily decision-making scenarios, Random:Draw delivers a pure, ad-free, and distraction-free user experience focused entirely on convenient and fair random selection. App Features Custom Offline List Management : Create, edit, add, delete, and batch manage custom participant lists completely offline. Modify list content anytime to adapt to different activity scenarios. All list data is saved locally in real time, ensuring flexible and personalized random selection for every use case. Fair & Accurate ...
阅读全文
 Word Flash is a clean and privacy-focused offline vocabulary learning tool that helps learners memorize English words efficiently based on the Ebbinghaus forgetting curve and spaced repetition system. Build your exclusive personal word bank, review unfamiliar words scientifically, record customized notes and example sentences, and track your learning progress — all without any network connection, account login, or data uploads. Designed for language learners, exam candidates and self-study users, Word Flash delivers a pure, distraction-free vocabulary learning experience focused entirely on long-term memory consolidation. App Features Science-Backed Spaced Repetition Learning Master vocabulary with the standard Ebbinghaus forgetting curve algorithm. Rate each word as Known, Unsure or Unknown after every flashcard review. The app automatically arranges personalized review schedules, intelligently screens new words and pending review words, and helps users avoid forgetting vocabular...
阅读全文