Short version: Lethal Dose (LD50) collects no personal data. It has no internet permission. No accounts, ads or analytics. The only third-party library is Google's Play Billing library, which lets Google Play handle purchases. Your study progress is stored only on your device.
On this page
1. Summary
Lethal Dose (LD50), package com.honilusion.lethaldose, is developed by Honilusion. The app has no internet permission, so it cannot send anything anywhere even if it tried. No accounts, ads or analytics. The only third-party library is Google's Play Billing library, which lets Google Play handle purchases. All of your study progress — quiz history, starred flash cards, and achievements — is stored only on your device. Google Play Data safety: the developer states that this app does not collect or share any user data. This page explains how that works in detail.
2. Information we collect
None. We — the developer — do not collect any information from you or about you, because the app has no way to transmit anything to us or to anyone else. Your study progress is created and stored entirely on your own device and is never seen by us. Purchases are processed by Google Play under Google's own terms and privacy policy (https://policies.google.com/privacy). We do not receive your card or payment details.
3. Data stored on your device
The app stores the following locally, on your device only, in its own private app storage:
- Starred flash cards
- Quiz history and performance (answers, scores, timing, personal bests)
- Achievements you've unlocked and study streak/session data
- Settings and preferences (TTS voice, pace, delays, toggles)
- Saved in-progress quiz state, so a quiz, Pop Quiz, or Practice Exam can resume where you left off
- A small local crash log, kept only on your device, for diagnosing app crashes (see Backups and exports)
- A small local record of your plan type and the time Google Play was last checked, so your plan still works offline. It is excluded from backups and from the backup file you can create.
- Counts of which features you have used (never when, and never what you studied). They stay on your device unless you send a feedback report.
4. Data sharing
We do not sell or share your data, because we never receive it. There are no advertising identifiers, no ad networks, and no data brokers involved in this app.
5. Permissions
The app does not request the Internet permission. Because it uses Google Play Billing, the app also declares the standard Google Play billing permission and the network-state permission added by that library.
6. Backups and exports
Android device backup
Android's automatic backup is enabled, scoped to the study database and app settings. Diagnostic and crash logs and the local purchase record are never included. If device backup is on for your Google account, that scoped data can be included in it; this is Android's standard backup, not something the app sends itself. You can turn it off in your device's Backup settings.
Backup My Data (your own export file)
Advanced Settings lets you create a backup file of your own data (starred-card status, quiz performance, achievements, and study sessions) in a format you choose to save. This file is created only when you choose to create it, and it only goes wherever you save or share it — a folder you pick, or an app you share it to. The app never uploads or sends it anywhere by itself.
Export Diagnostics
Advanced Settings also lets you create a diagnostics report for troubleshooting. This report contains technical information only: app version and build info, database version, your device model and Android version, content health-check results (counts only, not content), saved-session and achievement counts, text-to-speech status, and any locally captured crash logs with stack traces. It does not contain your quiz questions, personal identifiers, or anything you've written. Like the backup file, it is only created when you choose to, and only leaves your device if you choose to share it.
7. Feedback you choose to send
Provide Feedback (Settings) is optional and only starts when you tap it. It writes your message and, if you leave the switch on, a report to a file and opens your own email app addressed to support@ld50tox.com. The report contains the app version, database version, your Android version and device make and model, how many study items each category holds, text-to-speech status, any crash or repair logs the app has recorded, and a usage summary of counts and totals: days studied, time studied, questions attempted and accuracy per category, which features you used and how many times, and your settings. It does not contain which cards you starred, any question text or numbers, the dates or times of your study activity (crash and repair logs, if any, show when they happened), a device or advertising ID, your location, your accounts, your email address, purchase or plan details, or a list of your apps. You can read the whole report before sending and turn it off to send only your message. Because it is sent by email through the email app you choose, your email address is visible to us when you send it. The app never sends it itself.
8. Text-to-speech
The Read Aloud feature uses Android's built-in text-to-speech system, which hands your request to whichever text-to-speech engine is set up on your device. The app itself sends no data anywhere for this feature. The selected engine is part of your device, not part of this app, and is governed by that engine's own terms and privacy practices. We do not control, and cannot guarantee, how that engine processes speech or whether it does so entirely offline.
9. Data retention and deletion
Your data lives only on your device — there is no server copy for us to retain or delete. You can clear specific progress at any time from the Performance Dashboard's Reset Progress options. Reset Progress does not remove purchases. They belong to your Google account; Restore purchases brings them back on any device. Uninstalling the app deletes its local database and preferences from your device (subject to the Android device backup note above). Any backup or diagnostics file you've exported stays wherever you saved it, under your control, until you delete it yourself.
10. Security
Your data stays on your device, in this app's private storage, protected by Android's standard per-app sandboxing. We do not implement our own additional encryption on top of that, and we do not claim the data is encrypted beyond what Android's app sandbox and your device's own disk encryption (if enabled) already provide.
11. Children's privacy
Lethal Dose (LD50) is a professional and graduate-level exam-preparation tool and is not directed to children. It collects no personal information from anyone, of any age, because it collects no personal information at all.
12. Purchases and plans
Lethal Dose (LD50) is free to download. Some content needs a premium plan bought through Google Play. Purchases are handled entirely by Google Play. The app only asks Google Play which products you own; it never sees your card or other payment details, and no account is created in the app. The app keeps a small local record of your plan and when it was last checked so your plan works offline: subscriptions keep working for up to 7 days if Google Play cannot be reached, and lifetime access stays on your device until Google Play says otherwise. Manage or cancel a subscription, request refunds, and redeem promo codes in Google Play. Restore purchases is in Settings > Plan.
13. This website
This website (ld50tox.com) sets no cookies and runs no analytics. Web fonts are self-hosted from this site's own server, so no font request is ever sent to a third party. The only outside link on this site points to the Google Play listing and, in this policy, to Google's own privacy policy for purchases; neither of those is a request made by this website itself. The web server keeps standard access logs (IP address and requested page) for about 14 days, for operational purposes only.
14. Changes to this policy
If this policy changes, the update will be posted on this same page with a new "Last updated" date above.
15. Contact
Questions about this policy or the app: support@ld50tox.com.
16. Disclaimer
Lethal Dose (LD50) is an independent study aid created by Honilusion. It is not affiliated with, endorsed by, sponsored by, approved by, or employed by the American Board of Toxicology (ABT), the Society of Toxicology, the United States Medical Licensing Examination (USMLE), or any other certifying body, testing organization, or exam provider. All organization, exam, and certification names (including ABT, DABT, and USMLE) are the property of their respective owners and are used only to describe the subject matter this app helps you study.
This app is provided for educational and entertainment purposes only, to help you learn toxicology and practice for exams. It is not medical, clinical, poison-control, or professional advice and must not be used to diagnose, treat, or manage any exposure, poisoning, or medical condition. If you suspect a poisoning or overdose, call your local emergency number right away. In the United States you can also call Poison Help at 1-800-222-1222.
Practice questions and study content were developed using reputable online sources, published scientific literature, and regulatory guidance, with the assistance of artificial intelligence (AI) tools, and were reviewed by the app's content author. AI tools can make mistakes. The questions are not actual exam questions and are not official exam materials. The Practice Exam is a study tool only; it does not predict or represent any real exam, and using this app does not guarantee a passing score or any exam outcome.
Study content may contain errors or become outdated. Regulatory guideline summaries are for study only and do not replace the official documents. Verify important information against current primary sources. The app is provided as is, without warranties of any kind, and Honilusion is not liable for any loss or harm arising from its use. This app is intended for adult learners.
Guideline and organization names (for example OECD Test Guidelines and ICH guidelines) are used only to identify subject matter and belong to their respective owners. Summaries here are paraphrased for study.
(c) 2026 Honilusion. All rights reserved.