N.M STUDIOLINK GUARD
☰
LINK GUARD · ANDROID

Android user guide

A quick start for scanning, link checks and understanding the result.

Get it on Google Play

Follow each numbered action in order. Labels may differ slightly depending on the app version and your device language. If an option is not visible, skip that optional feature and contact support.

01

Install and open Link Guard

  1. Open the Google Play link on this website.
  2. Check that the app is Link Guard – Code Scanner by N.M Studio.
  3. Tap Install and wait for installation to finish.
  4. Open the app. Read any permissions or subscription information before accepting it.
  5. Stay on the main screen to choose the feature you want to use.
What to expect: You should see the Link Guard home screen.
If it does not work

If installation fails, check storage space, Google Play account access and the device’s Android version. Try updating Google Play.

02

Select language and appearance

  1. Open the app settings.
  2. Find the language option. The device language may be used automatically.
  3. Choose your preferred available language, if desired.
  4. Select a color theme if your version offers this setting.
  5. Return to the home screen and confirm the text and colors changed.
What to expect: The interface uses the selected language and theme, where supported.
If it does not work

If a setting is missing, your installed version may differ. Update from Google Play.

03

Check a web address manually

  1. Copy the complete web address you want to check.
  2. In Link Guard, open the link-check feature.
  3. Paste the address into the input field.
  4. Start the check using the button shown in the app.
  5. Read the full destination address and the reported risk before deciding to open anything.
What to expect: A result should appear if the connection and checking service are available.
If it does not work

If no result appears, check your Internet connection. A failed check is not a safe result; do not open a suspicious link simply because checking failed.

04

Scan a QR code with the camera

  1. Open the QR/barcode camera scanner from the home screen.
  2. When Android asks for camera access, grant it if you want to scan with the camera.
  3. Hold the phone steady so the entire QR code fits inside the scan area.
  4. Wait for Link Guard to recognize the code.
  5. If the code contains a web address, review the address and safety result before opening it.
What to expect: The detected content should appear in a result view.
If it does not work

Improve lighting, clean the camera lens and move the phone slightly farther away. You can also use a saved photo of the code.

05

Read a QR code from a picture

  1. Save the QR-code picture or screenshot on your phone.
  2. Open the image/gallery scan option in Link Guard.
  3. Choose the picture containing the complete code.
  4. Wait while the app reads the code.
  5. Review the detected content and check the link before opening it.
What to expect: You should get a result without using the live camera.
If it does not work

Use a sharper picture with the full code visible. If the scan repeatedly fails, try the camera instead.

06

Scan a product barcode

  1. Choose the barcode scanner.
  2. Point the camera at the entire barcode so all digits and bars are visible.
  3. Wait until the barcode type and number are detected.
  4. If a product information search is available, open its result.
  5. Compare the product name or details with the physical package.
What to expect: Product details may appear when the online database has a matching entry.
If it does not work

Not every barcode is in the product database. Missing details do not mean the barcode is dangerous or invalid.

07

Check links in PDFs or downloaded files

  1. Open the PDF or file-check feature if it is present in your installed version.
  2. Choose the document or attachment using Android’s file picker.
  3. Grant access only to the file or folder required for the feature.
  4. If web addresses are extracted, review each one before opening it.
  5. For download monitoring, enable its separate setting only if it is available and you understand the requested access.
What to expect: Supported files and available checks should be shown in the app.
If it does not work

PDF link extraction and attachment inspection are different functions. Not every file can be scanned, and a clean result is not a guarantee.

08

Route supported links through Link Guard

  1. Open Android Settings.
  2. Open Apps and look for Default apps or Opening links.
  3. Find Link Guard if it appears as an available link handler.
  4. Choose the supported link-opening option provided by your device.
  5. Try a harmless web link from a compatible app and check what opens.
What to expect: Some compatible links may open via Link Guard first.
If it does not work

Android menus vary by manufacturer. Some apps open links internally and cannot be redirected by this setting.

09

Understand the warning and result

  1. Read the complete website domain, not just its display name.
  2. Compare the address with the website you intended to visit.
  3. Treat a warning or unknown result as a reason to verify the destination.
  4. If the message asks for a password or payment information unexpectedly, do not continue.
  5. Use an independently found official address instead of a questionable link.
What to expect: The result provides information to help you make a decision.
If it does not work

No online check can guarantee that a page is safe. Newly created scams may not yet be known.

10

Review and configure DNS protection

  1. Open Link Guard and find the DNS or Network Watch settings available in your installed version.
  2. Check which DNS provider Android currently reports as active.
  3. If you wish to use a supported filtering provider such as Cloudflare or AdGuard, select it and read the instructions shown.
  4. Approve the required Android network or Private DNS change yourself if your phone asks for confirmation.
  5. Return to the DNS status view and check that the provider changed as intended. If not, restore your previous setting.
What to expect: The active DNS status reflects the setting actually used by your phone, when Android makes it available.
If it does not work

A provider appearing in a list does not mean it is already active. Android menu names vary by device. DNS filtering cannot inspect every web page or block every malicious connection.

11

View current incoming and outgoing data traffic

  1. Open the Network Watch or network traffic view if it is present in your installed Android version.
  2. Keep this screen open while using the internet on the phone.
  3. Read the incoming (download) and outgoing (upload) traffic values separately, in Mb/s.
  4. Compare changes in the graph when browsing or downloading something safe.
  5. Remember that current traffic is not the speed limit of the connection or the mobile network.
What to expect: Traffic readings change as your phone sends and receives data while the view is active.
If it does not work

A reading near zero can be normal when no transfer is in progress. The view does not report the exact capacity or congestion percentage of the nearest base station.

12

Run the internet speed test

  1. Connect your phone to Wi-Fi or mobile data, depending on which connection you want to test.
  2. Open the internet speed test in Link Guard, if your version includes it.
  3. Start the measurement and allow it to finish without changing networks.
  4. Read the measured download speed, upload speed and latency.
  5. If you want to compare Wi-Fi with mobile data, switch networks and run the test again.
What to expect: The results describe the internet connection to the test service at the time of testing.
If it does not work

Results can vary because of server route, wireless signal, congestion and other traffic. The test does not measure the theoretical maximum speed of a nearby mobile mast.

13

Troubleshooting and support

  1. Update Link Guard from Google Play.
  2. Check whether the camera, Internet connection and necessary permissions are working.
  3. Restart the app and try a different, harmless input.
  4. Note the phone model, Android version, Link Guard version and the exact error message.
  5. Open Support from this website and send those details, without passwords or sensitive data.
What to expect: Support can use the version and error description to investigate.
If it does not work

If the app closes immediately after launch, report that separately. A reinstall may remove local settings and history.