Vững Lái: Following Distance

Tailgating alerts by phone AI

Only for iPhone

Free · Designed for iPhone. Not verified for macOS.

iPhone

Mount your iPhone on the windshield: Vững Lái watches the car ahead, measures the gap for your speed and speaks up when you follow too closely. Free. Vững Lái (Vung Lai) is a following-distance assistant that runs entirely on your iPhone. Mount the phone sideways on the windshield: the rear camera and on-device AI spot the vehicle ahead in your lane, estimate the distance, compare it with your GPS speed and warn you when you follow too closely. THE 2-SECOND AND 3-SECOND RULE, MEASURED FOR YOU • Canada: the 2-second rule, in km/h and metres. • United States: the 3-second rule, in mph and feet. • Vietnam: Circular 38/2024/TT-BGTVT for dry roads, with a 1-second reminder from 20 km/h below its speeds. • The region is guessed from your phone and can be changed in Settings. ALERTS YOU DON'T HAVE TO LOOK AT • Under the safe distance: the gap card turns amber, and is spoken once it lasts a few seconds. • Really close (under 3/4 of the safe distance): red, sounded at once. • Tones, vibration and voice prompts in English or Vietnamese. • Warning when the gap closes fast: "Careful ahead!". • Stop sign and pedestrian reminders. • Three sensitivity levels: Calm, Balanced, Sensitive. DRIVER ASSISTANCE ON THE PHONE YOU ALREADY HAVE • No extra hardware: a windshield mount is all you need. • Calibrates its camera by itself in the first minutes of driving and remembers the mount. • Scales back its work when the phone gets hot, to keep running smoothly. PRIVACY • Camera images and location are processed on the phone, never recorded or uploaded. • No account, no ads, no tracking. The app collects no data. SAFETY NOTICE Vững Lái is an assistance tool only. It is not a certified measuring device and does not control your vehicle; its estimates can be wrong, especially at night, in rain or fog, against the sun, or with a dirty windshield. The driver is always responsible for watching the road, keeping a safe distance and obeying traffic law. Set the app up before you drive, mount the phone where it does not block your view, and do not operate the phone while moving. Intended for licensed drivers. Requires iOS 17 or later. Support: vudanmax@gmail.com

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    Information

    Seller
    Dan Duc Vu
    Size
    91.4 MB
    Category
    Navigation
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    Languages
    English
    Age Rating
    4+
    Copyright
    © 2026 Dan Duc Vu
  • Developer Website
  • Privacy Policy