Privacy Policy

1Who we are

Flash Share is an app for Android and Windows for sending files between phones and PCs that are near each other. It is published by Cosmo Labz (“we”, “us”). This policy explains what the app does with information, what stays on your device and what other devices can see. Sections 2 to 7 describe the Android app; section 8 covers what is different in the Windows app.

2Information we collect

We, Cosmo Labz, do not collect any personal information. Flash Share has no servers of ours, and we cannot see who uses the app, what they send or to whom. The only outside service in the app is Google AdMob, which shows the ads (section 3).

3Ads by Google AdMob

Flash Share is free and shows ads from Google AdMob, marked “Ad”, on the home screen, in Activity and after a transfer is delivered. To choose, show and measure ads and to prevent fraud, the Google Mobile Ads SDK in the app collects and sends to Google:

• your device’s advertising ID;
• device and app information, such as the phone model, Android version, language and app version;
• your IP address, from which an approximate location can be derived;
• how you interact with ads, such as views and taps, and diagnostic information about ad loading.

AdMob never receives your files, file names, transfer history or the names of your devices. Google processes this data under its own privacy policy: How Google uses information from apps that use its services and the Google Privacy Policy.

Your choices. In the European Economic Area, the United Kingdom and Switzerland, Google’s consent form appears the first time you open the app, and ads are only requested as that choice allows; you can change it at any time in Flash Share under Settings, Ad privacy choices. Everywhere, you can reset or delete your advertising ID, or opt out of personalised ads, in your phone’s settings under Google, Ads. Ads you then see are not personalised.

4How a transfer works

• Only what you choose. Flash Share reads only the files or folder you pick in the Android file picker, or share into Flash Share from another app. It does not browse your storage on its own.
• Phone to phone. The files are sent directly to the phone you select, and the person on that phone has to accept before anything is sent. Nothing passes through the internet or any server.
• Encrypted and checked. Every connection uses TLS 1.3 with a certificate created on each phone. The first time two phones connect, both screens show the same pairing code so you can confirm you are talking to the right phone. Each file is verified with SHA-256 so what arrives is exactly what was sent.
• Where received files go. Files you receive are saved in the Download/Flash Share folder on your phone, where your other apps can open them like any other download.
• QR code. To receive with a code, your phone creates a temporary Wi-Fi Direct network with a random name and password and shows them, with your device name, device ID and certificate fingerprint, as a QR code on your screen. Only a phone that scans it can join. Transfers that arrive through that network start without asking again, because showing the code is your consent; the network is removed when you close the code and the transfer ends.
• Wi-Fi Direct. For transfers of 64 MB or more over a shared Wi-Fi, the receiving phone can create a temporary Wi-Fi Direct network with a random name and password so the two phones connect radio to radio; it is removed as soon as the transfer ends. When two phones have no Wi-Fi network in common, a phone with Flash Share open can keep such a network up so a nearby phone can connect to it; it is removed when you leave the app, turn the option off, or a shared network becomes available. You can turn Wi-Fi Direct off in Settings.

5What nearby phones can see

To find each other, phones running Flash Share announce themselves on the Wi-Fi network they are connected to, using standard local network discovery (DNS-SD/mDNS) and a local broadcast message. The announcement contains:

• the device name set in Flash Share (by default, your phone’s model name);
• a random device ID created by the app;
• the device type and platform (phone, Android);
• the network port the app listens on;
• the fingerprint of the app’s security certificate on your phone.

It does not contain your name, phone number, email, accounts, contacts or location. Other devices on the same local network can see this announcement. When Flash Share is in the background and no transfer is running, it stops its regular announcements; while the app is still running it stays registered on the network so it can receive.

With no shared Wi-Fi. While Flash Share is open on screen and Wi-Fi Direct is on in Settings, it also announces itself over Bluetooth Low Energy (a short packet with the device name and the first part of the random device ID) and, when Bluetooth is off, over Wi-Fi Direct service discovery — both can be received by phones within range without being on any network. While your phone keeps a Wi-Fi Direct network up for this (see section 4), the announcement also carries that network’s name and password so a nearby phone running Flash Share can connect. Connecting gives no access to your files: every transfer still needs your acceptance, and the pairing code for a phone you have not paired with before.

6What stays on your phone

The app keeps the following in its private storage on your phone. None of it is sent to us or to AdMob.

• Your device name and settings (colour, transfer tuning, Wi-Fi Direct, diagnostics).
• The random device ID and the app’s encryption key and certificate.
• Paired phones: their device name, device ID, certificate fingerprint and the date they were paired.
• Transfer history: the file or folder name, the other phone’s name, total size, number of files, date and whether it succeeded.
• For incoming transfers that can be resumed: the file names and folder paths in that transfer, their sizes and checksums of the parts already received.

You control all of it. Swipe a transfer away in Activity to remove it from the history, tap Forget on a paired phone in Settings, or clear Flash Share’s storage in Android settings. Uninstalling the app removes everything above. Files you received stay in Download/Flash Share until you delete them.

If you turn on Diagnostics, the app shows your Wi-Fi link speed and signal strength on screen to explain transfer speeds. This is read when shown and is not stored.

7Permissions and why they are needed

You can decline the nearby devices or location permission. Transfers then need both phones on the same Wi-Fi network and go through your router instead of a direct link.

8Flash Share for Windows

The Windows app, from the Microsoft Store or our installer, works the same way as the Android app: no accounts, no servers of ours, and files go straight between your PC and phones nearby over your network or a direct Wi-Fi link, encrypted with TLS 1.3 and checked with SHA-256. Every transfer to your PC needs your acceptance, unless you turn on Auto-accept for phones you have already paired with. What is different:

• No ads, no tracking. The Windows app contains no advertising or analytics code and sends nothing to us, to Google or to anyone else.
• What nearby devices see. The same announcement as in section 5 (device name, which defaults to your PC’s name; random device ID; device type and platform, PC and Windows; port; certificate fingerprint), sent as a broadcast on your local network.
• What stays on your PC. Your device name and settings (theme, received-files folder, Auto-accept, Wi-Fi Direct, opening the folder when files arrive), the random device ID, the app’s encryption key and certificate, paired phones, and the transfer history (file or folder name, the other device’s name, size, number of files, date, speed, the route taken and whether it succeeded), with the speed curve of the last transfer. A short log of Wi-Fi Direct connections (network names and times, for troubleshooting) is kept next to them. All of it is in your Windows user profile, in the app’s own storage for the Microsoft Store version (removed when you uninstall) or in %APPDATA%\Flash Share for the installer version (delete that folder to remove it). None of it is sent anywhere.
• Where received files go. To Downloads\Flash Share, or another folder you choose in Settings.
• Wi-Fi Direct. For transfers of 64 MB or more with a phone, your PC can briefly join the temporary Wi-Fi Direct network the phone creates, using Windows’ own Wi-Fi settings: it adds a Wi-Fi profile with that network’s random name and password, connects, and when the transfer ends deletes the profile and reconnects to the network it was on. While joined, the PC may have no internet unless it is also on a cable. You can turn Wi-Fi Direct off in Settings.
• Location permission. Windows treats scanning for Wi-Fi networks as location access, so it may ask whether Flash Share can use your location. The app uses it only to find the phone’s temporary network; it never reads, uses or stores your location.
• Firewall. The app allows incoming connections to itself in Windows Firewall so phones nearby can reach your PC. It does not open your PC to anything else.

9Sharing and selling

We do not sell, rent or share information with anyone, because we do not hold any. What leaves your device is the files you choose to send to another device, the discovery announcement described in section 5, and the ad data the AdMob SDK sends to Google, described in section 3.

10Security

Connections are encrypted and mutually authenticated with TLS 1.3, pairing codes protect the first connection between two phones, and every file is integrity-checked with SHA-256. The encryption keys are created on your phone and never leave it. No method of electronic transfer or storage is perfectly secure, but Flash Share is designed so that only the two phones in a transfer can read what is sent.

11Children

Flash Share is not directed at children under 13, and its ads are not intended for children. We do not knowingly collect personal information from children.

12Your rights

We hold no data about you, so there is nothing for us to access, correct, export or delete on your behalf. All data the app keeps is on your own phone and under your control, as described in section 6. For data Google receives for ads, use the choices in section 3 or Google’s own controls. You are welcome to contact us with any privacy question.

13Changes to this policy

If Flash Share starts handling information differently, we will update this page and its effective date before the change reaches the app, and mention it in the app’s release notes on Google Play.

14Contact