Privacy Policy — Streakline
Streakline is published on Google Play as "Streakline: Pocket CFD".
Last updated: 20 - 08 -2026
1. Who is responsible for your data
Streakline is developed and published by Farrel Kent, an individual developer based in Jakarta, Indonesia ("we", "us"). Under Indonesia's Law No. 27 of 2022 on Personal Data Protection (Undang-Undang Pelindungan Data Pribadi, "PDP Law") we are the Personal Data Controller for the limited processing described here.
Contact: farrelkentk@gmail.com
2. The short version
Streakline has no accounts, never asks who you are, and contains no analytics, advertising or tracking of any kind. The fluid simulation runs entirely on your device. Shapes you draw, images you import and results you generate never leave your phone unless you choose to share them yourself.
One thing does leave your device: the app checks with our purchase provider whether you have bought Streakline Pro, using an anonymous identifier that is not tied to your identity. Section 6 describes exactly what that involves. Nothing else is transmitted.
3. Data processed on your device only
The following never leaves your device. We cannot see it and it is not transmitted anywhere:
| Data | Why it exists |
|---|---|
| Shapes you draw | To run the simulation and, with Pro, to save them for reuse |
| Images and photos you import | Converted to a black-and-white silhouette on-device and used as the body in the flow |
| Simulation results, force coefficients, exported CSV | Generated by the solver on your device |
| Videos and screenshots you capture | Written to your device or handed to your operating system's share sheet at your request |
| Your free-draw count and Pro status | So the app remembers your entitlement between launches |
This is stored in the app's own storage, and uninstalling Streakline deletes it. The app's Android system backup is switched off, so none of it is copied to your Google Drive.
The one exception is a file you deliberately share or save out of the app. Once you send a PNG, video or CSV to your photo library, your files, or another app, that copy is yours and is not removed when Streakline is uninstalled.
4. Camera and photo access
If you use the import feature, Streakline asks permission to take a photo or open an image from your library. The image is processed entirely on your device to extract its outline. It is not uploaded, not stored by us, and not shared with anyone.
You can refuse this permission and everything except image import works normally.
5. Screen-recording detection
On Android 15 and newer, and on iOS, Streakline uses the operating system's screen-capture signal to pause the simulation while your screen is being recorded or mirrored, including AirPlay. This applies to everyone, not only people who have bought Pro.
The operating system tells the app a single yes/no value: whether capture is on. The app does not read, store or transmit anything about what is on your screen, and no data of any kind is collected through it.
6. Purchases
Streakline Pro is a one-time purchase. There is no subscription and nothing renews.
RevenueCat, Inc. (United States) provides our purchase infrastructure. Being precise about the timing matters: its software starts when the app starts, before you have done anything, so the app knows whether you already own Pro and can show the correct local price. That happens for every user, including those who never buy anything.
From that moment RevenueCat receives:
- a randomly generated anonymous ID created on your device — not your name, email, or any account identifier
- your IP address, from which an approximate country is derived
- basic technical information: platform, operating system version, device model, app version
If you buy Pro or tap Restore Purchases, it additionally receives the purchase receipt from Google so the entitlement can be validated. It never receives your name, email address, or any content you create in the app. We do not set any user attribute, advertising identifier or custom identifier on it.
Google Play processes the payment itself. We never see or handle your card details, address or any other payment information. Google is the seller of record and its handling of your data is governed by the Google Privacy Policy.
Purpose: to deliver the purchase, to show the correct price, and to prevent paid features being unlocked without a valid purchase.
Lawful basis (PDP Law Article 20): performance of a contract with you, once you buy; and our legitimate interest in operating a paid tier for the ownership check that runs before any purchase. Using the app offline prevents all of it — the simulation needs no connection.
Retention: RevenueCat retains purchase records for as long as our account with them exists, because a one-time purchase must remain restorable indefinitely. You can ask us to delete yours (see section 10), though doing so means it can no longer be restored.
7. What we do not do
We prefer to be specific rather than vague, because "we may collect" language usually hides something. Streakline contains no:
- user accounts, sign-in, or email collection
- advertising SDK, advertising identifier, or ad network of any kind
- analytics, crash reporting, telemetry, or usage measurement
- location access, contacts access, microphone access, or device fingerprinting
- cookies or web trackers
- sale or sharing of personal data with anyone, for any purpose
We have no server. There is nowhere for your simulations to be sent even if we wanted them.
8. Permissions we ask for, and why
| Permission | What it is for | What leaves your device |
|---|---|---|
| Internet | Checking whether you own Pro and fetching the local price | Only what section 6 describes |
| Camera | Photographing a sketch to use its outline | Nothing — processed on-device |
| Photos / media | Importing one image you choose as the body in the flow | Nothing — processed on-device |
| Detect screen recording | Pausing the simulation while your screen is recorded or mirrored | Nothing |
| Vibrate | Haptic feedback on the controls | Nothing |
Camera and photo access are optional. Decline them and everything except image import works normally.
9. International transfers
RevenueCat is based in the United States, so the anonymous ID, your IP address, the device and app information described in section 6, and — if you buy — the purchase receipt are transferred outside Indonesia. Google likewise processes payment data on infrastructure outside Indonesia.
Under Article 56 of the PDP Law we rely on the contractual safeguards in our data processing agreement with RevenueCat. If you are in the EEA or UK, the same transfer is covered by Standard Contractual Clauses in RevenueCat's data processing terms.
10. Your rights
Under Articles 5 to 13 of the PDP Law you have the right to:
- be informed about how your personal data is processed, and by whom
- access your personal data and obtain a copy of it
- correct or complete inaccurate personal data
- delete or destroy your personal data
- withdraw consent you have given
- object to processing, including automated decision-making and profiling
- restrict or suspend processing
- receive your data in a portable form
- claim compensation for a violation of the law
Because Streakline holds no account and no identifier we can look you up by, the practical route for most of these is your device itself: uninstalling the app removes everything held locally, and your purchase record can be deleted on request.
To exercise any right, email farrelkentk@gmail.com. We respond within 3 x 24 hours where the
PDP Law sets that deadline (correction, withdrawal of consent, restriction of processing),
and otherwise within 30 days. Please include your Google Play order ID — it looks like
GPA.1234-5678-9012-34567 and is in your purchase receipt email — so we can locate the
record.
If you are in the EEA or UK, the GDPR and UK GDPR give you materially equivalent rights, plus the right to complain to your national supervisory authority.
If you are in California, we do not sell or share personal information as the CCPA/CPRA define those terms, and we do not use it for cross-context behavioural advertising.
Complaints in Indonesia: the PDP Law provides for a supervisory authority (Lembaga Pelindungan Data Pribadi). As at the date above that body has not yet been formally established; complaints in the interim are handled by the Ministry of Communication and Digital Affairs (Komdigi). Please contact us first — we would rather fix it directly.
11. Security and data breaches
The strongest protection here is architectural: we hold almost nothing, so there is almost nothing to lose. Data on your device is protected by your device's own security and the operating system's app sandbox.
If a personal data breach affecting you nonetheless occurs, we will notify you and the relevant authority in writing within 3 x 24 hours of becoming aware of it, as required by Article 46 of the PDP Law, describing the data involved, when and how it happened, and what we are doing about it.
12. Children
Streakline is a technical tool intended for users aged 13 and over and is not directed at children. We do not knowingly collect personal data from children.
Indonesian law treats anyone under 18 and unmarried as a child and requires a parent or guardian's consent for processing their personal data. If you are under 18, please use Streakline only with your parent or guardian's permission, and have them make any purchase.
If you believe a child's personal data has reached us, email farrelkentk@gmail.com and we will delete it.
13. Changes to this policy
If we change how Streakline handles data we will update this page and the date at the top. Material changes — in particular adding any form of advertising, analytics or account system — will be announced in the app before they take effect.
14. Contact
Farrel kent Kuntadihardja Jakarta, Indonesia farrelkentk@gmail.com
This policy describes Streakline version 1.0.0