Firefly Jar
Firefly Jar Privacy Policy
Effective date: October 25, 2026
App: Firefly Jar for Android (package com.vincentcheng.fireflyjar) · Developer: DaoYi Studio · Contact: [email protected]
This policy explains what data the Firefly Jar app ("the app", "we") and its website handle, why, and with whom it is shared. The app is a focus timer. It requires no account, and we do not collect your name, email address, contacts, location, photos or any other personal information. The only time data leaves your device to a service we operate is when you choose to share a night sky with friends (section 6).
1. Data stored on your device
The app keeps the following in its private storage on your device:
- your focus sessions: start and end time, planned length, activity tag, outcome (completed, flew away, given up) and the firefly species caught
- the session in progress, so it can continue after the app is closed
- your settings: sound, ambience, vibration, grace period, reduce motion, jar and night style, app language
- whether you own the Lantern Pack (a copy of the answer from Google Play)
- whether you used the "call it back" ad tonight
We cannot see this data. Deleting the app deletes it.
2. Android backup
If backup is turned on for your device, Android may include the data above in your device backup, which Google stores in your Google account. When you set up a new device or reinstall the app with the same Google account, Android may restore it. These backups are made and kept by Google under the Google Privacy Policy; we have no access to them. You can turn backup off in your device settings.
3. Notifications
With your permission, the app shows a notification when a session ends while the screen is off, and a silent reminder when you leave during a session. Notifications are created on your device and involve no server.
4. Purchases (Google Play Billing)
The Lantern Pack is sold through Google Play. Google processes the payment and tells the app whether you own the product; the app never sees your payment details. Google's handling of purchases is described in the Google Play Terms of Service and the Google Privacy Policy.
5. Optional rewarded ad (Google AdMob)
The app shows no ads during focus sessions or anywhere else, except one case: when a firefly flew away, you may choose to watch a short video ad to call it back. Only when you tap that button does the app start the Google Mobile Ads SDK and request an ad from Google AdMob, a service of Google LLC. To serve the ad, measure it and prevent fraud, the SDK may then collect and process:
| Data | Purpose |
|---|---|
| Advertising ID (Google Advertising ID) | Ad delivery, frequency capping, personalization where permitted, fraud prevention |
| IP address and approximate (country or city level) location derived from it | Ad delivery and regional compliance |
| Device information (model, operating system version, language, screen size) | Ad delivery and performance measurement |
| Ad interaction data (impressions, clicks) and diagnostic data | Measurement, fraud prevention, improving ad quality |
This data is shared with Google and, through Google's ad network, with advertising partners, as described in the Google Privacy Policy and How Google uses information from sites or apps that use its services. If you never tap "call it back", the Ads SDK is never started and none of this applies.
Consent in the EEA, the UK and Switzerland. Before the first ad request, the app asks for your consent with Google's consent message (Google's User Messaging Platform) and requests no ad until you have made a choice. You can review or change it at any time in the app under Settings → Privacy options.
6. Shared night sky (optional)
If you choose to create or join a shared night sky, the app signs you in to Firebase Authentication (a Google LLC service) anonymously: no email address, no password and no name is required, and the account is a random identifier that we cannot link to you. It is created only when you first open the night sky, never before. With that identifier the app stores, in a Firebase Realtime Database that we operate:
| Data | Purpose |
|---|---|
| Your anonymous user identifier | Tells your fireflies apart from your friends' |
| The display name you type (up to 20 characters, anything you like) | Shown to the people in the same sky |
| One entry per focus session you complete while in a sky: the firefly species and the time it was completed | Draws your fireflies in your friends' sky and counts tonight's catch |
| The sky's invite code, creation time and the time you joined | Lets friends who know the code join, and makes the sky fade after seven days |
This is all that is shared: no focus minutes, tags, streaks, device information or anything else from your device. Only the members of a sky can see its fireflies; anyone who knows the invite code can see the display names in it and join it. Choose a name you are comfortable showing, and share the code only with people you want in your sky.
Retention. A sky stops accepting members and fireflies seven days after it was created. Leaving a sky removes your membership and your fireflies from it immediately; the last member to leave deletes the sky. Anonymous accounts that have not been used for 30 days are deleted automatically. To delete your data sooner, leave the sky in the app or write to the contact below with your invite code.
Optional Google link. If the app offers it, you may link a Google account so the same sky follows you to a new phone. We then receive the Google account's identifier and email address from Google and store nothing else; you can sign out in the sky sheet at any time, which returns you to a fresh anonymous account. Google's handling of sign-in is described in the Google Privacy Policy.
Firebase is operated by Google LLC under the Firebase terms and may process this data on servers outside your country.
7. Website
The Firefly Jar website at game.daoyidh.com/fireflyjar, where this policy and the support page are published, is a set of plain static pages on our own web server (nginx), reached through Cloudflare. It sets no cookies, runs no scripts, uses no analytics and makes no requests to third parties. To deliver the pages and protect them from abuse, our server and Cloudflare process your IP address and the details of each request (the time, the page requested and your browser type). Our server keeps these access logs for 14 days for security and then deletes them. Cloudflare processes the requests as our network provider, as described in the Cloudflare Privacy Policy.
8. Children
The app is suitable for all ages. It collects no personal information, and ads, when you request one, are limited to Google's general-audience content rating.
9. Changes
If this policy changes, the new version is published at this address with a new effective date.