User Guide
From the GPS speedometer and ODO/TRIP tracking to fuel management, carburetor tuning records, oil change records, and maintenance records — here's what each of the 5 tabs can do, with screenshots.
Cars
Start by registering your car in the Cars tab. You can register multiple vehicles and switch between them — trip logs, fuel records, tuning records, and maintenance records are all kept independently per vehicle.
Open the registration screen from “+ Add Vehicle” in the vehicle list. Enter a name and year, and choose the model/engine from the dropdowns — if your car isn't listed, tap “+” to add it on the spot.
Cars tab: vehicle list
New registration form
Match the speedometer's background color to your car's interior. Just pick a color from the color picker in the registration form, and it's reflected on the Drive screen.
Custom color setting
In simple (immersive) display, you can place your own image above and below the meter. Transparent PNGs work best for emblems or logos. Adjust size and distance (position from the meter) with the sliders.
Meter custom image
Tap a vehicle in the list to open its detail screen, where you'll find entry points for “Maintenance” and “Tuning Records.” From here you can view and add records specific to that vehicle.
Vehicle detail screen
Maintenance
Keep a complete log of inspections, repairs, and servicing. Quickly check things like “When did I last change the tires?” or “When was the last inspection?” Access it from “Maintenance” on the vehicle detail screen.
Record the date, mileage, category (choose from the dropdown, or add a new one with “+”), work description, cost, shop, and notes. You can also filter the list by category.
Maintenance list
Maintenance form
Setting Record
From “Tuning Records” on the vehicle detail screen, log your carburetor adjustments. Keeping before/after data means you can instantly return to the setup that worked best.
Choose the carb type (dropdown, or add one with “+”) and set the number of carbs (1–8). Jet sizes can be set as “same for all carbs” or “individually,” supporting multi-carb setups.
Record the turns for the air and fuel screws individually. Enter a baseline setting and the app automatically calculates and displays the change in turns and degrees. Also record the resulting mixture (rich / good / lean) and temperature (low / good / high), plus any notes.
Tuning records list
Tuning record form
Drive
Displays real-time speed via GPS and automatically tracks ODO (total distance) and TRIP (segment distance). With background GPS, tracking continues even while using other apps.
By default, tracking starts automatically whenever the app is open. Turn on “Manual Start/Stop Tracking” in the Settings tab to control tracking yourself with the START/STOP button on the Drive screen.
Drive screen: normal display
Waiting to START (manual mode)
Turning on “Background GPS” in the Settings tab keeps tracking distance even when the screen is off or you're using another app (like navigation or music). When off, tracking only happens while the Drive screen is open.
The meter dial has three display modes. You can switch between them by swiping left or right on the meter. The dots at the bottom indicate the current mode.
Fuel gauge mode
Clock mode
Flip the switch in the bottom-right of the meter to enter immersive mode, showing the meter alone in full screen — great for visibility while driving. Tap again to return to the normal view.
Immersive display
The app supports a custom URL scheme starting with “vcmonitor://”. Write this URL to an NFC tag and place it on your dashboard, and tapping your phone against it will automatically open the specified screen — handy for starting tracking the moment you get in.
URL for each screen
| URL | Opens |
|---|---|
| vcmonitor://cars | Cars (vehicle management) |
| vcmonitor://drive | Drive (speedometer screen) |
| vcmonitor://fuel | Fuel (fuel tracking) |
| vcmonitor://oil | Oil (oil change records) |
| vcmonitor://setting | Settings |
Writing an NFC tag
Writing to an NFC tag isn't a feature of this app itself — you'll need a general-purpose NFC writing app. Write the URL above to the tag as a “URL/URI record.”
Fuel
Just log the amount and mileage every time you fill up, and the app automatically calculates estimated remaining fuel, range, and average economy — solving the “how much farther can I go?” question for vintage cars with smaller tanks.
Enter it from “+ Add Fill-up” in the Fuel tab. Supports both “filled to full” entries and entries where you know the “remaining fuel after filling.”
Fill-up history + stats
Fill-up form
Once you've logged enough fill-ups, you can view your fuel economy trend as a graph. Switch between “full-tank method” and “interval economy.” Units can be switched between L/gal in the Settings tab.
Fuel economy chart
A “Share” button appears on any fill-up record where fuel economy was calculated. Tap it to generate a meter-styled image card summarizing that record's fuel economy and distance, then share it or save it via the standard share sheet.
The card's background color uses the custom color you set when registering the vehicle, so your car's personality carries right through into the image.
Fuel economy share card
Oil
Log the date, mileage, brand, and viscosity together in one place. Oil management matters especially for air-cooled engines. Set a reminder interval so you never miss the next change.
Enter it from “+ Add Oil Change” in the Oil tab. Along with brand, viscosity (dropdown, or add one with “+”), and amount, you can also check off whether the gasket and filter were replaced.
Oil change history
Oil change form
Based on the “oil change interval” (distance / time) you set when registering the vehicle, a reminder appears at the top of the Oil tab as the next change approaches. Use it to avoid missing a change.
Setting
Adjust language, units, startup behavior, and GPS behavior to match how you use the app.
| Setting | Description |
|---|---|
| Language | Switch the display language between Japanese and English |
| Distance | Switch the distance unit between km and mi |
| Volume | Switch the fuel unit between L and gal |
| Start | Choose which tab opens when the app launches (Cars/Drive/Fuel/Oil) |
| Drive Display | Set the Drive screen's default display mode (speedometer / fuel gauge / clock). Can be switched temporarily by swiping while driving |
| Manual Start/Stop Tracking | When on, control tracking with the START/STOP buttons. When off, tracking starts automatically while the app is open |
| Background GPS | When on, tracking continues even while using another app or with the screen off |
Use “Backup” at the bottom of the Settings tab to export all your data (vehicle info, trip logs, fuel records, tuning records, maintenance records, and more) as a JSON file. When switching phones or reinstalling the app, restore your data by loading that file with “Import.”
Backup
Data
Trip logs, fuel economy, and maintenance records are all stored on your device only, and are never sent anywhere else.
See our Privacy Policy for details.
FAQ
The GPS speedometer and ODO/TRIP calculate speed and distance from GPS signal. Depending on reception — in tunnels or dense urban areas, for example — there may be some error or delay compared to actual speed/distance.
Check that your device's location setting is set to “Always Allow.” Depending on the device, you may also need to exclude the app from battery optimization in your OS settings — check your device's manual for details. Note that if the OS force-quits the app, tracking can't continue during that time (this is a platform limitation).
Select a vehicle from the list in the Cars tab, and Drive, Fuel, Oil, Tuning Records, and Maintenance will all reflect that vehicle from then on. ODO/TRIP, fuel records, tuning records, and maintenance records are all stored independently per vehicle.
Yes, reinstalling clears the data stored on your device. Export a backup from “Backup” in the Settings tab beforehand, then import it after reinstalling to restore your data. We recommend the same steps when switching to a new phone.
No — all data is stored on your device only, with no automatic transmission or backup to external services. Backups must be created manually via export/import.
