# Friction Circle Monitor > 4wheel Real‑time tire force & grip visualizer. For practicing trail braking Canonical page: [https://chrome-stats.com/d/io.github.kajimae.frictioncircle](https://chrome-stats.com/d/io.github.kajimae.frictioncircle) ## Overview - **ID:** `io.github.kajimae.frictioncircle` - **Platform:** Android - **Type:** Android app - **Status:** Available - **Publisher:** Hirotaka\_k - **Category:** AUTO\_AND\_VEHICLES - **Downloads:** 27 - **Version:** 14.0 - **Last updated:** 2026-07-27 - **First published:** 2026-03-18 - **Publisher country:** JP - **Size:** 2.56 MB - **Data as of:** 2026-09-10 - **Store listing:** [Google Play Store](https://play.google.com/store/apps/details?id=io.github.kajimae.frictioncircle) - **Privacy policy:** [https://sites.google.com/view/masatuen-prprivacy-policy/%E3%83%9B%E3%83%BC%E3%83%A0](https://sites.google.com/view/masatuen-prprivacy-policy/%E3%83%9B%E3%83%BC%E3%83%A0) ## Description [Functions]
This app is suitable for practicing trail braking.
■ Overview
Most G-meters only show the motion of a single point at the center of the vehicle.
This app uses smartphone sensors to physically estimate the vehicle’s dynamic state
and visualizes the effects of driver input and load transfer as the behavior of each of the four wheels.

It allows you to intuitively understand,
“how much grip each tire is using right now,”
in real time while driving.


■ Key Features

● Independent friction circle for each wheel
The app displays how much each tire is being used in the longitudinal and lateral directions in real time.
You can visually identify behaviors such as rear load loss during trail braking into a corner,
or insufficient traction when accelerating out of a turn.

● Vehicle-parameter-based simulation
By entering vehicle parameters such as front/rear axle weight, tread, wheelbase,
center of gravity height, and friction coefficient,
the app reflects load transfer and tire usage according to your vehicle’s characteristics.

● Unique two-stage calibration
The app uses a two-step calibration method that independently defines the gravity axis
and the vehicle’s forward direction.
This allows accurate extraction of longitudinal and lateral G,
even when the smartphone is mounted at an angle.

● Technical details
https://github.com/H-kajimae


■ How to Use
1. Temporarily mount the smartphone in the in-vehicle holder (angled mounting is acceptable).
2. Launch the app and define the level reference while the vehicle is stationary.
3. Tilt the device in the vehicle’s forward direction to define the forward axis.
4. Follow the on-screen guide to return the device to its original position and fix it securely.


■ Functional Limitations
This app is an information visualization tool intended for analysis and observation.
It does not provide instructions, recommendations, or guarantees regarding driving operations,
driving decisions, or display accuracy.


■ Disclaimer
Regardless of whether this app is used,
driving a motor vehicle (including on public roads and race tracks)
is inherently a dangerous activity.
All decisions regarding driving and continued operation
are the sole responsibility of the user.

This app does not guarantee driving safety or outcomes.
Displayed information may contain errors or delays.
Any damage arising from the use or inability to use this app
is the responsibility of the user. ## Rankings - #2,488,863 — Overall ## Permissions and access ### Permissions - `android.permission.ACCESS_NETWORK_STATE` - `android.permission.INTERNET` - `com.android.vending.BILLING` - `com.android.vending.CHECK_LICENSE` - `io.github.kajimae.frictioncircle.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION` ## Similar extensions and apps - [Traction Circle G-Force Meter](https://chrome-stats.com/d/com.speed_wiz.traction) — 7,653 users, 4.00 / 5 - [G Force Meter](https://chrome-stats.com/d/com.omeratalay.gforcemeter) — 157 users - [G-Force Meter](https://chrome-stats.com/d/com.gforce.gforce_meter) — 47 users - [Finding Grib](https://chrome-stats.com/d/com.findinggrip) — 14 users - [G-Circle - G-Force Meter](https://chrome-stats.com/d/io.github.tkskojima.gcircle) — 16 users - [SpeedChart GPS Speedometer](https://chrome-stats.com/d/com.ydn.speedtest) — 140 users - [G MATER](https://chrome-stats.com/d/com.lunadropstudio.gmater) — 55 users - [Apex Dynamics](https://chrome-stats.com/d/com.hotlaps.dynamic) — 28 users - [ForceMeter: G-Force Tracker](https://chrome-stats.com/d/com.rcpl.forcemeter) — 16 users - [G-Force Meter: Acceleration](https://chrome-stats.com/d/com.simonj.gforcemeter) — 1,087 users - [Tread Log](https://chrome-stats.com/d/com.rubber.tread.tread_log) — 22 users - [G Force Meter: Accelerometer](https://chrome-stats.com/d/com.itfarmhouse.gforcemeter) — 348 users --- Source: [Chrome-Stats](https://chrome-stats.com/d/io.github.kajimae.frictioncircle)