Short Summary
EM Chrono (com.medielsoft.emchrono) by MedielSoft is intended for adults aged 18 and over. Policy version: 2026-11-03.
Last updated: November 3, 2026
EM Chrono is a mobile application for measuring muzzle velocity and related values from a Bluetooth chronograph, especially the EM9800BL device. It is intended for airsoft measurements, replica tuning, and indicative power checks based on BB weight.
What the App Does
- connects to a chronograph using Bluetooth Classic SPP / RFCOMM,
- shows paired Bluetooth devices, allows Android system selection, or manual connection by MAC address,
- can trigger Bluetooth pairing including PIN or passkey entry if required by the system or device,
- receives chronograph data in real time,
- shows individual shots, velocity, average, minimum, maximum, spread, RPS/RPM, energy in joules, temperature, and humidity when provided by the device,
- allows switching m/s and FPS, calculating energy from velocity and BB weight, creating BB profiles, and saving measurement series to history.
Data the App Processes
Bluetooth device identification
- device name, alias, MAC address, and optionally RSSI and Bluetooth device class,
- the last connected chronograph for automatic reconnection if this option is enabled.
Chronograph data
- shot velocities, rate of fire, temperature, humidity, and possible device error codes.
User-entered data
- BB profile names, caliber, BB weight, measurement names, and measurement notes.
Data Storage
- Measurement history and BB profiles are stored locally on the device in the app's SQLite database.
- Simple settings such as language, last BB weight, last connected device, and display options are stored locally using SharedPreferences.
- Local data can be deleted in the app or by clearing app data in Android settings. Depending on system settings, Android may include app data in a system backup and restore it later; the system and user control these backups.
Measurement History
For a saved measurement, the app may store the measurement date and time, name, note, projectile name, caliber, BB weight, shot count, average velocity, RPS, device error information, and individual measured shots.
For individual shots, the app stores shot order, velocity in m/s, and optionally temperature and humidity. The user can edit a saved measurement name and note, delete the measurement, or export it to CSV through the phone's share sheet.
What We Do Not Do
- The app does not include user accounts, registration, or user profiles.
- We do not send measurement history to the operator's server.
- We do not sell personal data.
- The operator does not run measurement analytics or a separate crash-reporting service; Google advertising SDKs do process diagnostic and interaction data.
- The PIN/passkey is used only for Bluetooth pairing through Android and is not permanently stored by the app.
Permissions
- The app uses Bluetooth permissions to discover, display, pair, and connect to the chronograph.
- On Android, it uses BLUETOOTH_SCAN and BLUETOOTH_CONNECT.
- The manifest also contains legacy Bluetooth permissions and location permission for compatibility with older Android versions and some device manufacturers where location is required by the system for Bluetooth scanning.
- The app itself does not determine the user's GPS location, does not store location coordinates, and does not use camera, microphone, or contacts.
Sharing and External Services
- CSV export is shared only when the user explicitly uses the share function. The data is passed to the app selected by the user in the Android share sheet.
- External links to the MedielSoft author website, FALLENS Airsoft shop, the ballistics app on Google Play, and the Discord community open outside the app in the system browser or another external application.
Bluetooth Data
The Bluetooth MAC address and device name are used only to find and reconnect to the chronograph. These details are not used to track the user and are not sent to MedielSoft servers.
Google AdMob Advertising and Consent
The app uses the Google Mobile Ads SDK (AdMob). When an ad request is permitted, Google automatically collects and shares the IP address (which can indicate approximate location), device identifiers including advertising ID and app set ID, app and ad interactions, and diagnostic data such as performance or crash information. Purposes include advertising, ad measurement and analytics, and fraud prevention. Personalization depends on your choices, service availability, and applicable requirements. Advertising data is encrypted in transit using TLS.
The app does not pass measurement history, notes, BB profiles, or Bluetooth MAC addresses to the advertising SDK as ad parameters. The advertising SDK independently processes the device and usage information described above.
Before requesting ads, the app refreshes consent information through Google User Messaging Platform (UMP) and shows a form when required. The app does not load ads unless UMP permits requests. When UMP requires a privacy entry point, you can change your choices under Ad privacy options in Settings. You can also reset or delete the advertising ID in Android settings.
Google processes and retains advertising data according to its policies. Deleting a local measurement or uninstalling the app does not by itself erase information already processed by Google. See Google Privacy Policy, How Google uses information from partner apps, and Advertising SDK data disclosure.
Optional Ad Removal
When available, the remove_ads_lifetime one-time product permanently removes advertising through Google Play. Measurement, history and export remain free. Google Play processes payment and records ownership under its own terms and privacy policy. The app does not receive payment-card details or the Google account password.
The app receives purchase status and a signed receipt containing the product identifier, purchase token and related order information. The signature, app package, product and purchased state are verified on the device. The receipt and signature are stored locally to preserve ad-free ownership offline; they are not sent to a MedielSoft server or passed as advertising parameters. Purchase acknowledgement and ownership restoration use Google Play Billing. Restore purchase is available in Settings with the same Google Play account. Clearing app data or uninstalling removes the local receipt, not the purchase record held by Google. A successful store refresh can reflect refunds or revoked ownership.
Your Choices and Rights
- You can delete saved measurements directly in the app.
- You can remove local app data by clearing app data in Android settings or uninstalling the app.
- To the extent provided by GDPR, you may request access, rectification, erasure, or restriction of processing of personal data.
Contact
If you have questions about this privacy policy or want to exercise your rights, contact us:
MedielSoft
Email: erdt.martin@medielsoft.cz
Website: https://www.medielsoft.cz